Thanks for the advice, guys. I'll check out those places you suggested.
So let me ask you why you recommend to steer clear of eBay? The dealers I'm looking at have been in business for quite a few years. They have between 200 and 1000 positive feedbacks. I've read the feedbacks and everyone is very happy with the cars they bought. Cars like Mercedes, Porsche, BMW, and such. I would definately be buying a warranty wherever I get a car because I am familiar with how expensive Porsche's can be to maintain.