The first one is a Chevrolet Corvette Z06. Once again I couldn't get the wheels to look right. I also forgot to add the exhaust. What can I do to get the vent by the front wheel to look right?

The second one is a Ferrari F50. I don't really see anything wrong with this one, except for the fact that it has no wheels.

They are quite good , anyway you need to draw the wheels better , and the vette is way too narrow , sport cars are wide and low , and if you want you can draw em a little lower and wider than they actually are to make them look more agressive , but never draw em higher nor narrower... only my .02