Top gear is automotive themed entertainment not a documentary. Anyone who has ever worked on cars knows this. You can bet there was a lot of off camera hackery to get the truck running each time. It didn't just drive away.

I used to pull these trucks (well, all sorts of vehicles) apart for a living. If you pulled the same stunt 10x with 90s Hiluxes and 90s Rangers you'd have more Rangers driving away in one piece because they have a better (taller web specifically) frame and that was the the weak point (at least in topgear's test it was).