You can run up a hill next to Gadgetzan to get along the walls, I thought it might lead to getting onto the roofs, but I ended up stuck between some inanimate objects and a wall
I built a car in Half-Life 2 with Garry’s Mod by placing wheels on a piece of metal, then adding thrusters for steering. I also added some lamps on the front to see where I’m going. The key thing is using a Pod to encase the player so they don’t fall off all the time
Another shot of the ridiculous jeep I built. It actually drives pretty well, I assigned the thursters to 8 and 9 so I can steer, and 7 drives the wheels.