. They're a very race oriented BMW company. They even have a team that competes in the Koni Challenge series and Grand Am series. They're extremely knowledgeable about performance, especially with M3's. Bavarian Autosport
as mentioned above is a great company for styling mods, performance parts, tools, replacement parts, and cool gadgets. JleviSW
is another good website particularly for styling mods and aftermarket lights etc.
I've also purchased a lot of products through Umnitza
in California for lighting upgrades including headlights, DRL harness, Angel Eyes, interior lighting, etc.
Also, check out Bimmian
for aftermarket lighting and styling mods as well.
I hope this information helps you find what you're looking for.