Check in the Gigs section of the local Baltimore craigslist [yes, craigslist has been getting hit hard here lately but its still a great place to use] and maybe post something about needing a car for the shoot in exchange for prints. thats what we do here in Raleigh every summer for photo shoots. We'll get someone to bring up their muscle car, classic car, whatever, and do a barter/trade for the car. Works every time. As the other person answered, car clubs are great for that as well, and these too are listed on craigslist... the enclosed photo is one of the ones i took using this trade/barter system. the guy got some nice photos of his Camaro, and i got what i needed...

You might want to contact some of the local car clubs in the area to see if any of their members will let you use or rent their vehicle. There is a listing of car clubs on OldRide at the following link - [url]http://www.oldride.com/clubs/index.html[/url]