When the truck Grubeck steals to chase after Spike is shown pulling out of the impound lot of the police station the rear shutter of the trailer is open. During the chase itself several shots show the shutter is now closed most likely to hide the pyrotechnics loaded into the trailer for the impending explosion at the end of the chase.
When Lawlor is being abducted by the ghost Grubeck, it is very obvious that a person in a black ski mask and black clothes is driving the car.