Not a stunt, they folk who attacked or swore at them were real folk along the highway.
Seen the whole program a couple of times.
Yes they are very good and my grandkids love the program. There has been some spin-offs but these guys are still the tops.
Somewhere on the web must be were they have to convert a car to not just drive it along the road but also in the water.
They are always moaning about folk who drive along the narrow roads over here towing a caravan(small fifth wheeler to you).
Well the challenge was to send them all away for a weekend in a caravan, they managed to crash it whilst leaving a petrol station after filling up, next they spent a bad first night and decided to make breakfast in the van, not only did they set theirs on fire but also the folks next door as well.