I've brought three old volkswagen busses over from europe (through Tacoma).  Two of the three times I was charged a $149.99 "steam cleaning" fee.  Seems all they were looking for was dirt in the tire treads.  The first bus I brought over was a rare dump truck model and even after they 'steam cleaned' it, a few pounds of dirt fell from the frame and such when we lifted it up with the forklift and placed it on the trailer.  What a scam.

... beyond that, I paid a few dollars for port fees but nothing to customs due to the age of the vehicles and that they don't fall under any of the smog or safety rules.