So My Character Owns A Truck

[Kenpachi Zaraki]

Depending on what you would exactly want to do with it, you could just make it a Super Move. Like the truck rolls up, you hop in and run them down before it disappears into a plot hole. Or the mount could have an AI that initiates the attack, possibly making it an assist but less powerful. For it to be around for significantly longer and operated by the Prime, it'd get a bit sticky. Maybe make it a Utility super move that grants resilience, speed and the Run Them Over move at the cost of limited maneuverability/easier to hit and inability to use other moves?