Here is a good site for locating dealers and contact info: Car Dealer Ratings, New, Used Car Dealership Reviews, Locator | Carfolks.com
Good old cold calling can be effective when done right. Avoid calling at the end of the month and the first day or two of a new month. Develop a value laced opening statement that will peak the interest of your client. You're going to have to either ask for an appointment in person or tell them you're going to send them an e-mail with more information. I would even consider a webinar appointment. Here's what I would do.
Hello is (customer first name) there?
I hope I didn’t catch you at a bad time?
This is (your name) calling from (company name). NO PAUSE HERE, KEEP GOING!
The reason I am calling is to let you know about an exciting new accessory dealers at are installing on Corvettes and Camaros. Customers love our product which will help you sell more vehicles while making higher grosses. I am going to send you an e-mail with pictures/videos and more information, what e-mail address should I send this to? I'll also follow up with you tomorrow, would you prefer a morning or afternoon call.
When I sell Phone Ninjas, I try and get dealers to jump on a webinar with me at that moment. I'll even have a webinar open and ready to go. I then direct them to the gotomeeting web page and provide the info to join me. I've closed deals in 20 minutes using this approach. So consider this approach as well.
Good luck.