The art of trying to insert ones head into the anus of your partner during intercourse.
Yo Jim, I just did a mexican U-haul on that chick and now my face smells like tacos!
mexican U-haul: define #2
a really shitty, old pickup truck that has random junk piled at least three feet over the cab, so as to make the shape of a U-Haul truck.
hey look at that mexican U-Haul two lanes over!