sonictheory,
beforei'd liek to comment...i want to disclaimed..thisis all constructive critiqism..
don;t take it personal~..
IMHO,your photo's are underexposed and wrong WB setting.
the composition is not interesting and the colours is not attractive..
it doesn;t potray and unique or talents in the photo's nontheless..it's very amatuer..
some of them were off focus and and the colour is poor~
what you can do to imporve the images is to edit them extremely~,,
sumthin you can try is
-increase the saturation/contrast
-try different colour balance/colour mix/levels(colour correction)
-masking in photoshop may help
-cropping to get a better framing
-get wild with it.
-get more image reference from internet(supercar website, imported magazine sites)
p/s - be patiant and don;t think what other might think when you are taking photograph..i feel that when you are taking those images, you weren;t very prepared and was rushing...probably because of the hot weather?...