Some good ideas here, C&C per req:
1. The classic shot, unfortunately, this one doesn't quite work. The DoF is just too shallow, and the flags are cut off, which wouldn't be bad, but in this case, it should be symetrical. I do however like the beads of water. NICE touch!
2. A nice composition idea, however way too much DoF here; the house and trees in the background don't really add anything. As well the deep shadows below each car are somewhat distracting. An ideal position for this one would have been to set yourself up (if you could) so that both foreground cars pointed to the background one equally.
3. Not a big fan of unusual angles. Again, too much DoF and note the rather distracting reflections in the paint.
4. A great composition, see previous comments on DoF.
Overall, some very nice car shots, which are a difficult area of photography.
Just my $00.02 worth - your milage may vary.
~John