I think this is one of your best HDR's yet. This picture has me thinking is it a photo or HDR...or better yet real or fake...This is the type of HDR I like the ones that make you think a bit and really look at all the detail to figure how it was done. GOOD JOB!!
I have a little advice for shooting cars as I used to take photos of cars. If you can find the corner of the bumper and back off from that point and and keep the camera a little lower or higher depending on what perspective you want. It really gives a much more attractive vibe when shooting angle shots of cars and its always nice to see the front end/grill of the car a little bit.
Maybe you could try this on your own car and see if you like that perspective before you go out and waist a bunch of time and shots and see if you like this approach.