ok, i made this tut for the ppl that might be having some trouble changing the paint color of a car in photoshop...and just a pretty simple and fast way to change the color
open the car you want to chop in ps
select the entire car except the tire/wheels using the lasso toolVVV

now still using the lasso tool, hold alt and deselect the windows/lights/etc._notice the lasso now has a - after holding alt VVV

now go to image>adjustments>desaturate VVV

now go to image>adjustments>variationsVVV

here you can easily change the color with a few clicks (just click blue a bunch of times with a little green if you want as example) and then to the right, you can darken or lighten up paintjobVVV

here is a few example that i did to show you guysVVV
and remember, if you dont like the outcome of the color, just press control/alt/Z at the same time to go back to the desaturated part or 2 times to go back to the original color
then to start over and make a new color, desat or go to variations again and do thisVVVV

click the "original" like above and then click the colors you want
and you can also do this b4 u start changing the colors......when you have the car selected (paint only), and still have the lasso tool out, right click over the car and select "layer via copy" to make a copy of only the paint.......then you can have a bunch of different color layers to switch through after you change the color of each layer to find the color you like best
Fo Sho,
HKSevo