Originally Posted by Mark Chen
4000 included painting and installation?
Yes, 4K+, I forgot the exact number. However since this is a dealer added option it obviously varies from dealer to dealer.
I recommend buying the parts yourself and find a good bodyshop to install them. The parts themselves are $1200 for the M-kit and $600 for the carbon fiber diffuser. You get a nice 10% discount if you're a BMWCCA member ($45/yr membership fee)