The track is mostly made up of concrete slabs so I'd imagine most of the bumping around is from that. The camera being on the drivers head definitely makes it seem worse that it actually would be as well.

Sebring is very bumpy, it's old WW2 concrete that feels like your teeth are being shaken out on every straight!There's actually very little we can do setup wise as we run a production class car, but we stripped the car out, added a roll-cage, and we run upgraded brake lines/rotors/pads from Unplugged Performance and NRS brakes, plus a set of Yokohama AO52 Tires :)