I have provided the link to their existing website which I will rebuild after this logo is complete. The only thing you should take from that site is that they want classy, not crazy. Other then that, the old stuff is getting scrapped.
I think a little carbon fiber may do nicely for this. Maybe some brushed aluminum or even a fresh coat of paint. Your the artist. I'll be quick with feedback.
As far as fonts go, serif is fine but nothing to stylized like zapfino. He may go for the san serif look where she may not. Your choice.
He has played with the idea of making "CSS" (steve's collision center) t-shirts and other merchandise so maybe play with those letters. It could be a quick way to his heart. ;)
They've always used new cars in their logos but every couple of years, those become outdated due to new model releases. If you'd like to use a car(s), keep that in mind. My advice would be to stick with the classics.
Lastly, Steve is a muscle car die hard! He owns an old '68 Firebird and a '69 Camero SS (his favorite, something ridiculous like 700 horses :) so perhaps you may want to play with some of those elements.
Oh yeah, she hates dark websites so I'll obviously be building them a lighter/whiter one. Keep that in mind when considering contrast.
Thanks for all your hard work and good luck - David