I've got two ideas but i don't know if i can do either of them:

1st, when you say "keep it to one specific enviroment" is that a rule or could i make a vehicle that is made to travel across ice but can burrow through into the water below and act like a sub.

2nd, does the vehicle have to be for humans or could it be for cartoon insects like in "A Bugs Life"

I think i like my second idea better.