I'm a little disappointed that they measured vibration with electronic sensors. They've found more creative ways to do that in the past, like in that driving-on-a-bumpy-road myth where they used glasses filled with water or something. But I guess that would've been too fragile here.
If I remember the bumpy road myth correctly, they were able to get up to speed before going over the bumps, which allowed their measurements to be fairly accurate... in this case, they would have lost all of their water before they got anywhere near fast enough to notice an improvement.
I enjoyed this episode. Part of me found watching the truck shake itself to pieces to be thoroughly entertaining. The conjoined cars myth was ok, not overly interesting.