2. The radiation would have been blown out the muffler or could drip onto the ground.
Apparently anyone doesnt count those who know the smallest bit about how radiation works.
Radiation does not drip. It is not a fluid. It "Radiates" (hence the name), exactly how depends on whether we are talking about Alpha, Beta, or Gamma Radiation, but none "Drip", and I'm fairly sure dont pose a threat if they hit the road. Alpha and Beta particles wouldnt effect the driver or its occupants, Alpha paricles can be blocked with paper, IIRC Beta particles need a little more, but not much. The threat would be Gamma Waves (and X-Rays), which arent even a particle, much less a liquid that could "drip". You need something dense, like lead, to stop those.
Nuclear waste is another question, as nuclear waste emits radiation, that is a protential problem, but I do not know if it was a problem in this specific vehicle design.