PORTAL VEHICLES ADDITION

I don't know if it is possible to make drive able more vehicles in portal community lobbies,but it would be fantastic. For example to make the truck with trailer that is just a decorative vehicle driveable like the tanks, helicopters or jets. To make normal civilian vehicles drive able also... This brings more experiences creativity like making a race, a challenge where you have to deliver a trailer to some point etc. Or even adding for example a big plane like a C101 or something heavier and bigger to maps experiences for example to be defended and attacked from jets.