In photography circles you always hear taking pictures at sunrise and sunset gives dramatic shots. For people and skylines I agree but for cars give me a blue sky with big white clouds. Look at the difference between the 2009-05-31 shots and these.
On the evening of June 3rd I played with an off camera flash unit with something called a diffuser on it. This diffuser looks like a small clear plastic bucket. The idea is to soften the light, although it works best when it has something to bounce light to (like a ceiling).
It is pretty easy to position a strobe, behind the car, which will properly light the roof, hood and side of the car. For the front either you need a flash (on or near the camera) or maybe some of the drag strip lights can be repositioned (like that idea, can anybody crawl up a pole?).
On other thing on strobes and flashes, if it is not windy, when the light hits the smoke from the burn the picture does not look very good. Daytime is so less complicated.