Need Trigger help

[Golden-Chimera]

I've been wondering from the map "-once in- The City of Drugs", the car trigger they used. If there was no hero/unit in the car, it wouldn't drive...for my part, i want to take the trigger and make it so only a HERO can enter a vehicle, on my part is going to be a "mech" so people won't have 3000 mechs. So im guessing i would use something like the burrow abilitys with peons, but making it not move/attack without a hero in the transportation slot is slightly on the difficult side for me, please answer my plee for help!