Just some of my 2cents on shooting cars. I absolutely don't claim to be remotely good at it, but I have gotten lucky a few times.
As mentioned before, a circular polarizing filter, if you can affix one will dramatically reduce unwanted glares. From stripes, sun, glass, reflections, etc..it works well at letting you see through the surrounding elements to the car.
Front tires, always. always. always show the rim to the camera. Unless you are trying to go with certain lines on the ground, nobody wants to look at tire tread. Direct the front wheels to show off the rim to the camera.
Height, I prefer either a high point of view, or a low/tire height point a view.
Surrounding area, I like to keep the vehicle in it's "natural habitat". For our cars, that is road or perhaps concrete..for my Jeep it's dirt, rocks, mud, whatever.
Post processing of pictures (digitally altering them) is the only way to fly. Taking shots directly out of the camera and spreading them will hinder the photo's look. Altering saturation, shadows, highlights, contrast, white balance, etc will help the look in almost every photo you take.
This is less than a minute worth of altering. Also consider if this was shot with a .raw type file, you can basically go in and readjust every aspect of the shot ..
Force flash, every camera has a force flash option. When I shoot with my SLR, I almost always have the flash forced OFF. It allows the lens to do the work to get a cleaner shot. However if you are a spot, even in broad daylight, that casts a shadow that you want to see (grille or wheels are usually what gets hidden), forcing the flash will provide fill light that will help the car/subject look more evenly exposed.
If you are trying to shoot a car in motion and have the ability to adjust the shutter speed on your camera. A shutter speed that shows the car in sharp focus yet too slow to stop the motion of the tires helps show the actual action of the car, it will also blur the background. Cranking up the shutter speed or letting the camera do it will stop the background and tires from turning...making a pretty boring "still" shot
Some helpful reading, though I may not agree with
all of it
http://photography-on-the.net/forum/showthread.php?t=70290http://photography-on-the.net/forum/showthread.php?t=536323