I think it is the artistic bug in you coming out a bit. I can do some pretty cool things with Photoshop, but I have no real artistic tallent. I know how to use Photoshop to get what I want, and I can "paint" cars pretty well while using it. This is definitely gratifying.
Skinning is fun. It is creative and it is cool. But racing is more fun. I do find when I get a little tired trying to improve my times, or I just don't feel like driving, a little skinning can be just the ticket.