$400 should be able to get you a good entry level DSLR like the T3 type of camera. Check out craigslist if you are fine with buying something used. You'll always want better glass to go with it too so look at different brands and see what lenses they offer aand what the price points are. Canon usually runs a little less expensive on glass.
For getting a good exposure of angel eyes, here is what I would do. Try a slow shutter speed (several seconds and on a tripod) and play with aperature and ISO until you get the amount of light you want. Once you get the headlights the way you want play around with lighting the car in different ways. Using an off camera speedlight would be the preferred way if you're not doing a full studio shoot. With several seconds of the shutter being open you have time to run around the car and pop the flash. It might take awhile to get the shot just the way you want, but you'll learn a lot about exposure doing it this way.
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