I don't think the ones that showed up were the best ones to make the trip. If Bobby had as much time as the ones ahead of him I think he would have been a lot faster. Also, the Oversized buggy hit the right side and was still top 5.
It's really hard to beat a rig that is tuned to work in those conditions. The bouncers just have a big motor and big tires. Not really any less motor though in many cases.