yeah, shots are coming along well, and if you get yourself some flashes, your night time will change forever.
also like DC said, since the background is already going to be blown out (or completely white) don't be afraid to push a bit further into the over exposed area and you'll make the colours of the car pop. Light colours actually have more colours in them, so when you bring the exposure down in post processing, the car will still look normal
otherwise if you shoot too dark and try to bring the exposure up, you get something called "banding" which is where the colours separate because the computer is just taking a wild guess at what colour something should be, so it just groups like colours together, and you start to see lines.
Do like they do in Finding Nemo, but instead of swimming, "Just keep shooting"