"These build journal entries are part of a short series on the development of the E9X M3 / E8x 1M M Performance style carbon mirror caps by Karbonius Composites

This specific journal entry looks back at the intention behind this crowdfunding project along with the prototype development."
- Matt

The beginning of the end. 

BMW M GbmH has recently began discontinuing the M Performance product line for the E9X M3, starting with one of it's most sought after product: the carbon fiber replacement mirror caps. 

They used to be available for +/- 750 US for the pair. 

This trend has now continued on to the E90 M3 Performance Spoiler, and will likely happen to other M Performance products as the molds are not renewed. 

Close but not quite. 

I reached out to Ana @ Karbonius Composites back in December 2020. Known for their E46 M3 products, they had started expanding their catalog to the E9x M3. 

Their initial design were using a OEM ABS mirror cap with a pre-preg overlay, unlike the M Performance that used a negative mold to create a purely carbon cap. 

Karbonius was also using a variant of the 2x2 weave pattern by laying pre-preg carbon in a "split" design that separate the upper and lower part of the mirror cap. 

Doing it right, the OE way, with an OE+ option. 

Karbonius and I got together to develop a brand new set of 1:1 M Performance style replacement mirror caps with the added bonus of 1x1 weave option, matching the OEM CF roof by BMW M GmbH.

Ana & I convinced the product team to revise the design to the original M Performance.

The prototypes. 

The continuous 2x2 weave. 

The OEM BMW M Performance caps had a continuous 2x2 weave pattern. Karbonius matched this quite handily. 

3D printed brackets. 

The caps were also developed with 3D printed OEM style brackets for a perfect fitment, it is truly OEM per my test fit.

Pre-Preg Carbon.

The M Performance mirrors caps were complete pre-preg and autoclave carbon fiber.

The most obvious way to discern this OE level carbon process is by looking at the underside of the cover. 

This is purely carbon, there is no fiberglass or ABS plastic structure. 

Up next: I test fit the prototype and look back at the crowdfunding process & production.