I know our highest earning rep in Columbus area for sales in my company is female... and the best looking female in our sales office at that. Not to sound sexist or anything but it might be to your advantage. Some might be put off at first but they might be more even impressed that a "girl" would know stuff about cars. But that probably wouldn't matter any way. When you go into something like high end deals. Your customer usually would know what they want. They would have researched and compared then decided. You are not going to be dealing with people who 2nd guess themselves. You will have to put up with some snob types but might work out better then average retards.