I too have a 2001 proton w/ 48,000 miles
As mentioned the big things i would look for are;

1. accident damage
2. fluid leaks
3. unusual noises: engine knocks, rough transmission shifting, dif noises (my rear diff whines when cruising at 62mph, its being fixed under warranty but is expensive $2-3,000 plus)
4. wierd electrical behaviour

I think as a non origional owner your engine and drivetrain warranty is 60,000 miles / 5 years so you should be covered in the event of serious problems but confirm that.

If there is a service record, great, if not (like mine) I did a carfax check and it listed much of the service record in their report which was helpful, enough information that i knew service work had been done. As a safeguard i had all the fluids changed shortly after i got the car home.

All in all, for a limited production concept vehicle whilst not perfect, the VX has, in my opinion, remarkably few issues, all of which can be dealt with with a little advice from this invaluable board.

Good luck, I hope you go with the vehicross, i also was considering a yellow s/c nissan, the xterra, allready owning a 2002 Pathfinder i really like Nissan's but i'm so glad i went with the VX, i havent regretted it for a minute, the VX has waaaay more character.

Pete