Contact Vortex Media Group.

They operate several online titles: subdriven.com, swedespeed.com, mwerks.com, speedarena.com, triplezoom.com, vwvortex.com, thecarlounge.com. Vortex is widely recognized as one of the top auto enthusiast websites, regardless of brand. Ask about how you can offer the book for sale in their forums which have hundreds of thousands of readers. Specifically see if you can post it up in the regional forums and in the car lounge forums so you capture a wide audience. Send them a copy to review, I think it is likely to happen.

They also have good relationships with C&D, R&T, etc - so if they like it enough there may be some networking advantage there. All of the jounalists see each other with some regularity at new car intros, so who knows...

Good luck.