[LokRobster]

100mph with a missing wheel is anything but sensible! You should make the odds of wrecking reflect the danger :)

The slightest hazard (well, 2 hazards in a row) is going to cause Control Rolls, and with the 100mph speed penalty on the Crash Table they're really likely to be serious.

For ease of tracking, I'd roll for hazards every 0.5 mile (didn't Convoy do something like this?) rather than setting up road sections. The Skill Check suggested seems good. You could have the Hazard be debris for D1 on a roll of 1-5, or D3 Obstacle on a 6. Hit the hazard or make a deliberate maneuver (Drift, Swerve or Bend) one Difficulty higher to avoid.
If a hazard appears, I'd give a 1 in 6 chance that it's followed by a second hazard. If it's a rough road i'd up it to checking every 0.25 mile with a 2 in 6 chance of a follow-up hazard that forces control rolls. Worsen the odds for worse roads.

Really I'd slow down... losing your car to debris and hazards doesn't seem as fun as another fight.

Or maybe i'm paranoid since our July 4th duel I had Driver +1 skill in a HC2 vehicle and still spun out at 40mph doing a D4 bend...