"In this final entry to the series, The Strada CS finally get bolted in the Phoenix.

I chat air bag sensor, document my exploration of mounting options and final selection. I wrap up the series with my final impressions and an eye for the future."
- Matt

Safety on my mind.

Since 2021, I have been researching, testing and documenting integration of Recaro seats in BMW M chassis. I have found limited information available online, and have since invested time and money to test it on my own. 

I have come to discover that a significant portion of the available public information in online groups can lead you down high risk choices without proper understanding of the risks.

Seats are inherently complex - they bring together numerous aspects we value: aesthetics, comfort, position and more. Considering the intricacies, expenses add up: mounting solutions can cost 30 to 50% of the seat's cost.

In the cost : benefit analysis, the fundamental purpose of seats gets forgotten. Your most prized and value asset will be buckled onto this seat - and your passenger seat. 

In this entry, I do take a page out of the life insurance salesman's playbook - I highlight the risks, share my experiences, dispel myths and provide the rationale to my selection. 

Airbags. 

Modern BMWs have a variety of airbags across the car connected to suite of sensors that influence their deployment. Airbags are interconnected with your seat belts, crash sensors and other safety components into the DME and airbag control module. They provide a comprehensive safety envelope for yourself and others. 

Although nearly three decades old, the E46 M3 is still equipped with modern airbags in the A pillars, steering wheel, dash and doors. The more modern M cars have more airbags: they'll be found across the roof rails, seats, kick panels, rear door cards and other areas.  

While this entry is specific to the E46 M3, the logic applies to all BMWs. 

The occupancy sensor. 

To begin with, we need to chat about your passenger. The original E46 M3 seats have an occupancy sensor sewn into the original cover and cannot be-reused. 

The occupancy sensor is compromised of 30x individual pressure sensors across the mat. They detect and measure your passenger's weight. Past a certain threshold, the dash airbag and door airbags would deploy - below, it wouldn't. 

The practical uses are two fold: it protect kids & small adults along with reducing potential repair costs. The former is obvious, the latter is often left undiscussed. 

The risks. 

Many will recommend to loop the connector to delete the sensor, fooling the air bag control module and DME into believing the seat is occupied.

For road use, the risks are severe. 

If you get into an accident where airbags are deployed - and everybody is OK, you will unfortunately be threading a thin line with a value-destruction event: the salvage title.

Worse, insurance inspectors may void coverage altogether due to modification to safety systems. This is not legal advice - please consult your insurance agreements.  

Insurance companies are mandated by most juridictions to replace airbags with brand new components - and they are expensive.

As an example: the dash airbag (SKU 72126998950) is +/- 750 USD. while the A pillar airbag (SKU 72127495449) and door airbag (SKU 72127037233) are +/- 300 USD each. 

Furthermore, airbags sit behind panels that are designed and manufactured for effective deployment - in clear terms: they break apart. All panels and mounting hardware will require replacement. Lastly. we need to add labor and coding costs. 

All things considered, the fortunate situation in which passenger airbags shouldn't require deployment may add upwards of 10,000$ USD to repair and replace. 

In comparaison, the E46 M3's Genuine BMW occupancy sensor costs +/- 200 USD. At 1:50 cost ratio and the salvage title risks, I took an educated decision to go with the sensor replacement. 

The installation. 

The installation process was performed for the passenger Strada seat prior to re-installing the covers in the previous entry. My apologies for the visual confusion, this Series follows a logical order. 

The original occupancy sensor sits under the foam. The Sportster CS' lower shells presented a challenge - unlike the flat original seats, they had curvatures that could potentially break the sensors apart under load. 

The foam had 2x stripes cut off, allowing us to insert and sandwich the sensor flat. The front section had holes drilled out to allow fishing the connector through. The sensor has its own Genuine BMW module that sits under the seat and connects into the seat harness. 

This picture is taken from my prior installation of Pole Position ABEs. 

Myths & mounts. 

The OE+ solution. 

Back in 2021, I originally Pole Position ABEs with M-Texture inserts into the E46 M3. I sought a relatively cost effective solution to blend in the seats with the interior. This intention was carried over to the selection of the mounts. 

I selected the OE+ side mounts. Here, the OE+ nomenclature is due to its compatibility with the original BMW slider upon which the seat belts and their pretensioners are secured. 

it makes for a cost effective solution.

Additionally, they are optionally compatible with the original electrical motor powering the forward and backward movement. This proved of little value in my E46 M3: the back seats were inaccessible for adults even when fully forward. 

They are manufactured from 11 gauge stainless steel and finished in glossy powdercoat. The design of the side mounts left hardware exposed. It's not the prettiest thing - but it is highlight functional. 

The Sportster OE+ variant. 

The Sportster is a bottom mounted seat, as such the OE+ Sportster CS mounts had an entirely different design. We faced some fitment issues due to the thickness of the powdercoating. We enlarged bolt holes and cut the rear sections to avoid contact with the sliders. 

I sold the OE+ side mounts with the Pole Positions but kept the original BMW sliders and the wiring harness we created. I was hopeful the powered sliders would prove useful with reclining mechanism.

Upon test fitting them, accessibility issues were still a concern. While a good idea on paper, it didn't turn out to be useful on the E46 M3. I believe it would be on the M5s and more recent BMW M2/3/4 coupés.

Overall, the OE+ mounts are functional, affordable and safe designs. If you're looking OEM like fit and finish - they are not it. 

Recaro's EuroSpec.

With quality on my mind, I sourced the original Recaro EuroSpec mounting solution. They were originally developed when the E46 M3 was introduced - back then, Recaro Europe designed and engineered complete mounting solutions. 

The fundamental advantage: it replaces everything. 

The kit includes new floor brackets, sliders, slider covers, seat belt brackets,  reinforcement plates, accessories and complete hardware set to install it. As such, you do not need to transfer any hardware from the original seat, making for a straight forward installation. 

It's a popular kit in Europe as it is TUV/ABE certified, making them legal for road use. Unfortunately, these safety certifications do not apply little in North America. 

The downside is cost: the more extensive kit and the Recaro brand name makes it 2.5x to 4x the price of the OE+ mounts. It explains why it is relatively unknown to M3 owners. 

Modular design. 

Additionally, Recaro's Eurospec kit for the E46 M3 is modular. It includes height spacers: hollow steel bars that are sandwiched between the floor brackets and the sliders.

There are 2x configurations available.  The kit includes the required bolt lengths for each configuration. 

The Recaro instructions state the floor mounts and sliders on their own match the original height of the BMW mounting solution. As we'll discover later on, this does not mean you'll sit as on the orignal seats.

We proceed with installation, fitting the 30mm height spacer. Unlike the original BMW design, Recaro opts to fit the sliders above the floor line on brackets.

Recaro side mounts.

Additionally, the EuroSpec mounting solution is interoperable with Recaro's original steel side mounts to fit any of their bucket seats. To be clear, this does not fit with any of Recaro's bottom mounted seat. 

Height adjustments. 

Upon bolting the seats and the pretensioner - it was pretty obvious this was way too high for the most people.  At 6'1, it definitely was for me.

Still, seeing the seats fully assembled validated our choice to upgrade to the Recaro solution. The sliders and hardware are hidden away, along with the wiring harness wrapped into a plastic sleeve. 

Overall, it's well designed and well built. 

We removed the spacers and bolted the sliders directly on the floor brackets. The seat is then bolted from the bottom, sandwiching the seat belt brackets with the seat's frame. 

The moment of truth.

The Phoenix rolled out of paint in October 2024 and was towed to the upholstery shop to refit the complete interior and bespoke components. The Strada seats were the last component to be installed to finalize this phase of the E46 M3 interior program.  

To start, the bracket needed to be bolted into the floor nearest to the center console. Recaro designed it in this matter to make installation easier. I know from experience after I foolishly tried to fit the entire seat into the car with it bolted to the brackets. 

The floor brackets are fitted with original BMW bolts & plastic caps for sleek aesthetics. The airbag occupancy sensor was connected and harness was connected to the seat's plug. 

The last words.

The Strada series spawned 9 extensive entries, each taking 15 to 20 hours on average to create between research, photo-editing, copywriting & editing to create a cohesive storyline with as few typos as I can bear to revise. 

The series was then published to social media, in addition to editing accompanying video reels on Instagram. When combined with creating the seats themselves and recording all processes, we total over 300 hours dispersed over 18 months. 

We committed such effort to stay true to our intentions: to educate through transparency by showcasing our processes, abilities and creativity. I'm grateful for David and Louis' time and patience in sharing their knowledge to me. 

I'm hopeful we've achieved our goals, and I'd love to hear from you. Feel free to reach out to share your thoughts and request a quotation for the Strada CS here.

On a personal level, it's been a labor of love, passion and drive to meet ever evolving expectations I have for myself, my cars and Euroconnex. 

This is a brief pinch me moment. 

I love the Stradas - but more is planned to pursue our quest to upscaling the Sportster CS.

The plastic accessories will be replaced with machined aluminum components amongst other things.