LOL, I wonder what would've happened if one could steal materialistic stuff as easily as software...
The only serious businesses in the world will very soon become advertising and security, and when(not if) the later fails there'll be nothing left to advertise since everything's going to be FREE!
Oo, the mayhem it will cause...
I don't really have an economics degree to say anything for sure, but the very idea of downloading cars from the internet is absurd anyway so it doesn't matter.

The idea of a realistic virtual world sound cool as well, but don't forget that it's not all models. You'll have to have superb physics engine as well and god knows what else to make a really realistic world.
It will of course be even cooler if the computer(s) creating it will be just big enough so you don't loose it...

Benny