So I'm actually looking at this as a new consumer and a few notes on the experience (my first obviously)
1. The site is too wide. Annoyingly so, I don't know why I'm so put off by this but I literally have to widen my browser to get it to render correctly and it makes me uncomfortable. Considering how much empty space there is I'm not sure why its got to be over 1200px wide with no margins. YMMV I'm just one data point
2. I'm not comfortable with, what appears, to be the requirement to signup right away. I'm not clear on the process here, but I'd like to browse a bit without having to log in to anything. I also don't like not being to signup using facebook without having to give an email. Here's the thing car buying is one of those things where I hate giving out my contact info they tend to just be spam beacons. Let me do something without having to register my email address. I'd prefer to choose my car and options etc.
I'd honestly prefer to get to the point in the process where the only thing left to do is for me to pay you and you send my info to the dealers before I need to sign up.
3. Creating a log in without a password verification seems like a bad idea. What if I screw this up (or worse screw this and my email up)? By the way there's an issue with your reset password page. http://public.adifferentengine.com/files/badreset.png
4. I tried the car I want and I'm missing a bunch of option choices. I've got a pretty exact idea of the car that I want and there's a bunch of options that I can't choose. In my case I have a very exact idea of the car I want and I just want the lowest price from the dealers. Having to deal with negotiations based on price with varying options is a hassle I don't want to really deal with.
Anyway I'm not buying today but I'll probably give it a try "For Real" in the near future seems like something I'd want.