This one is (literally) jet-powered:
Powered by General Electric J-79 jet engine straight out of a F4 Phantom fighter jet, the big yellow school bus, which is the largest jet vehicle, does excitingly fast 350mph. This 42,000 hp, 10-foot-high, 35-foot-long bus blasts a 75-foot flame out its exhaust...
The bus driver, who wears a seven-layer Kevlar suit while operating this vehicle, has prior experience driving a jet-powered portable toilet.
http://www.gizmowatch.com/entry/jet-powered-school-time-jet-school-bus-sets-an-eye-on-350mph/.
It may be theoretically capable of doing 350, but no way it actually got clocked at 350 with the pictured design. You'd need wings/spoilers or something to provide down-draft and keep it all on the ground.
However, I believe that the only item on it which happens to be stock, would be the roof.
Minnesotastan has as much burn in that post as that bus. :P
I usually just throw down that "If you don't like the quality - contribute." and then drop the link for the upcoming queue.