They bought a new Ford Contour (what the white car was) for the rental place, of course. They were so afraid that the people would recognize Johnny Knoxville, thus ruin the skit, but that didn't happen.

For the toilet scene in the hardware store, they of course bought the toilet. The reason why Dave crapped his pants was because he had to go, and they made him stay in the van for hours (waiting until there were several customers in the store at the same time). And When he actually went in was later in the week, not later that day.

For the golfing scene, they met up with the two real angry guys at the clubhouse, bought them beers and gave them passes for rounds of golf to get the signed release.