[WickedBMW]

I've had few cars that I modified and few of them that were left untouched. Based on my experience every car that remained OEM never give me any problems. Every car that I modified had quite a few issues, especially with suspension and DSG.

I'm going to keep my current M3 mostly stock. Only thing I'm going to do is to modify exhaust, add wheel spacers, tint it and PPF front of the car.

With that said, why wouldn't manufacture put out a car that is already tuned and aesthetically ready so there would be no need for aftermarket parts? Manufacturers have extensive R&D department, so I'm pretty sure they can come out with a DTM street legal car. I would pay extra money if cars were coming off an assembly line aesthetically ready and tuned to the max capacity of an engine.

[DoubleDave]

All of the usual answers apply here:
The manufacturers strike the balance of performance and reliabillity (cost)

Regional regulations can determine things like how close to the fender the tire can be.

Many performance “enhancements” don’t make the car perform better, just look better (talking suspension here)

In some cases they leave room for their own aftermarket divisions.

I’m sure I’m overlooking a bunch of things.

[Brickologic]

Originally Posted by DoubleDave

All of the usual answers apply here:
The manufacturers strike the balance of performance and reliabillity (cost)

Many performance “enhancements” don’t make the car perform better, just look better (talking suspension here)

I’m sure I’m overlooking a bunch of things.

It depends who your aftermarket source is ...

Most aftermarket companies and brands like Akrapovic, Bilstein, Brembo, Eibach, H&R, KW, BBS, Sachs, Ohlins, Ronal, ATS, OZ, ... are the Source for the car industry of their aftermarket hardware.

https://www.kwsuspensions.com/bmw-motorsport

[DoubleDave]

Originally Posted by Brickologic

It depends who your aftermarket source is ...

Most aftermarket companies and brands like Akrapovic, Bilstein, Brembo, Eibach, H&R, KW, BBS, Sachs, Ohlins, Ronal, ATS, OZ, ... are the Source for the car industry of their aftermarket hardware.

https://www.kwsuspensions.com/bmw-motorsport

Of course you always have to consider the source. The big players that you mention do work with the OEMs and put time and money into development and can produce a quality aftermarket option.

It’s when companies either rush to market because they want to be first or when they know customers will accept an underdeveloped product because they need to ‘fix’ the stance on a car is when you get junk.

I’m all for choices and the freedom to do what you want with your own car, It’s a pet peeve of mine when vendors say “We’re gonna fix the horrible stock suspension” and give you an underdeveloped product that struggles to even achieve the aesthetic goals let alone any performance improvement.