In all the talk of graphical downgrades no one seems much preoccupied with 'why?'. Why build something and then proceed to tear it down, piece by piece, in the hope that ever more diminished expectations about the final product won't be severe enough to...
Look out for tacks on the road, for they'll slow you down and make you crash.
Use your double-jump to get extra air over the big gaps.
Don't forget to spend your coins to upgrade your vehicle when you get the chance.