Go to the parking lot in Leisure Park and there should be a motorcycle and a car.

If you go down in the tunnels and then go in reverse back up, they will both be there again too.

Get the truck and go into the tunnel, make a left and follow it all the way down.

There will be a working truck and a truck that doesn't work - go into the big double doors then come back out and the truck will be brand new (respawned).