"In this entry, I share my notes on the quasi final fitment of the E92 CSL Carbon Trunk Redux on the Stripper.

I focus on what matters: I zoom in on the finer details and compare with the previously installed fiberglass imposter back in 2022." 
- Matt

3 years and counting. 

This Series begun in May 2022 with "Sourcing a discontinued classic."  and evolved into a 3 years long tumulus rollercoaster of lows, mirages, deserts and highs - this is its final entry.

As of Summer 2025, my E92 M3 is unfortunately still collecting dust in storage as work on building a fresh S65 and documenting the continued development of the S65-EVO.

I made due with the cards I was dealt and proceed with removing the original trunk and fitting the CSL carbon trunk Redux. This entry is exclusively focused on its fitment. For more technical information on the original trunk and fitment, I covered it in a previous entry here. 

Below are my notes on installation, fitment and interior dilemmas. I also edited a reel here. Feel free to comment on Instagram and reach out in my DMs to chat. 

I'll cut to the chase: the trunk's fitment met my expectations upon its first closure. 

Notes on on-car lights fitment.

The variable that most influences the precision of any trunk's fitment is the inner tail light fitment.

Any significant gap or offset between intersecting body panels with the trunk lights will immediately draw your attention. This would be made worse on light and bright colored cars. In this regard, Fire Orange might be one of the most unforgiving color to test on. 

In the previous entry, we test fitted the lights on the trunk after paint and found them to be perfect - it boded well. With little surprise, on-car fitment followed through: lines around the lights match perfectly. 

As an installation tip, I recommend to firmly slide the taillights and its tab over the edge of the trunk, and lower the light into its cutout - holding it firmly as you bolt the light's bracket against the underside of the trunk.   

Notes on adjusting overall fitment. 

The second most impactful variable on quality of fitment is the placement of the trunk on its hinges. The 4x bolts' positions dictate the overall placement of the trunk from left to right, and front to back. 

We made life worse for ourselves by overcompensating on adjustments on the first attempt. The final position ended up matching the original's. It is discerned by a lack of any faded & flaked Fire Orange paint on the hinges as seen of the pictures below. 

As an installation tip, prior to bolting the trunk to the hinges; you should thread the upper bolts on each side of trunk.The hinges are slotted and fully opened in this location, allowing you to slide the trunk onto the hinges without requiring a second set of hands. Torque down the bolts gradually at all 4x location to avoid damaging the inserts.  

Notes on height adjustment. 

The final component that influences fitment are the trunk bump stops on both sides of the trunk. Adjusting their height will influence the inclination of the trunk, most noticeable with tips of the trunk near the junction with the quarter panel and rear window.

On the 4th picture below, I exaggerated the adjustment and increased its height to showcase the impact. For the final fitment, we kept them to the previous height of the original metal trunk. 

The bump stops will also influence the smoothness of the latch's open/close operations. If you do adjustments here, make sure to test how it easily it closes and releases. 

Notes on new hardware. 

I used 4x brand new bolts as the originals are painted at the factory and tend to flake upon removing or bolting them down. 

I considered using new hinges from BMW as they come in black primer. As we now know, this would have made likely made fitment a game of trials and errors to reset the correct position. 

Additionally, I'm unsure if black hinges would have been an aesthetic improvement over the original color matched hinges. 

Notes on strut(s). 

As we're talking about hinges, this is a reminder that this trunk weighs +/- 15 lbs less than the original metal trunk.

Consequently, I recommend you fit 1 of the 2 struts to avoid damaging the bolts' inserts from the trunk rocking back and forth off the hinges - after having potentially knocking yourself out in the process. 

Notes on underside dilemmas. 

The interior of the trunk presented a few dilemmas surround safety and accessibility during servicing and aesthetics. This is where you make your own choices.

Safety & accessibility. 

BMW updated the trunk designs on all 2009+ E9x M3s by removing the key-lock; it's a sleek design that I assume reduces theft potential and [...] likely cut costs.

However, the M3 V8s do not integrate an emergency release cable under the rear seats like an E60 M5 for reasons beyond my pay grade. If you don't have fold down seats or the ski pass, you're out of luck and will need to connect the car using the engine bay nodes. 

The E9x M3 exclusively uses a release handle that connects with the trunk's latch via a metal wire. It is fished through the trunk, into a white plastic bracket into a small slotted plastic section of the liner.

It all comes together to allow you to pull on the handle with sufficient force without tearing the liner apart.

Without the liner, it floats around like this.    

Your options. 

Ultimately, the desire to showcase the Redux trunk's sublime interior carbon work has some potential compromises. 

If I was to run without a trunk liner, I would do away with the white plastic clip and tuck the handle away, taping it await inside the trunk. Whenever I'd have to pull the latch, I'd have to pay attention to not damage the carbon. In the context of servicing this car in what could be a frustrating situation, this is a risk potential. 

I'm leaning towards creating an Alcantara liner instead of the grey carpeting. Carbon would still be visible and more attention would be paid to the paint line. If you're interested in one, please reach out to discuss. 

The final comparaison. 

Across series discussing carbon panels for my BMW M builds, I consistently discuss the need to evaluate aftermarket body panels in a holistic perspective. In simple terms: how much will you really be paying and what will you really end up with. 

This Series provides a unique opportunity to do a near side-by-side comparaison of a high quality CSL trunk versus a fiberglass replica based on my real world experiences

The baseline cost. 

The replica CSL trunks available from Alibaba are selling for +/- 450 USD with a hefty 1,300 USD shipping charge to North America. Most E92 owners will instead buy it under a house brand that imports in bulk and will pay roughly 1,500 USD shipped. As a reminder, I paid 1,200 USD shipped for my used trunk. 

At this price point, the trunk was made from fiberglass with carbon overlay on the exterior. The inner shell will be left in raw black finish on a new unit. Mine was previously painted Alpine White. 

The paint & body cost. 

The replica trunk required numerous adjustments to the shell in order to accurately fit all accessories, especially the inner trunk lights. Additional time was required for the electronic handle and license plate lights. 

The complete shell needed was then primed and the exterior shell needed to be block sanded to level out imperfections in order to achieve a proper OEM finish. Afterwards, the complete trunk was painted in Fire Orange, clear coated and wet sanded and polished across visible areas.

The paint & body process cost me +/- 1,200$ excluding taxes - in 2022. 

For +/- 2,700 USD, I ended up with a trunk similar in weight to the original metal unit with significantly worse fitment. 

The REDUX option. 

The CSL carbon trunk Redux by Vorsteiner retails for 3,000 USD + shipping. It is a complete carbon trunk that weights 5.9 kg / 13 lbs.

The production units are available with no cost finish options such as ready-to-spray primer on the exterior shell, and clear coated interior shell, reducing the subsequent paint and body expenses. 

From my experience, the Redux trunk does not require adjustments nor body work. It will exclusively require paint work on the exterior shell to color match with your E92. 

The expected final cost will be in the high 3,000 USD range depending on local rates for paint work. 

For my build, the price difference was a no brainer - and I can't buy 3 years of my time back anyways. 

I rest my hat on the Redux trunk; it is the highest quality CSL trunk option for the E92 M3. 

I'd like to extend thanks to the team at Vorsteiner for supporting this project and seeing it through to the finish line. 

Thank you to the customers who pre-ordered this trunk. Some of you have been waiting a long time - and I'm grateful for your patience and trust.