TGUK lost its edge, and my interest, when the scripted bits became too obvious. The UK producers apparently couldn't be bothered fussing over the most obvious clues to how contrived an 'incident' was and, after a bit of clumsy editing, just let go to air anyway. Unfortunately this lack of attention to detail is creeping into TGUS - the cardboard box challenge being an example.
I'm sure the most inattentive US viewer would have wondered how two guys on a high-lift forklift managed to add an extra layer to the arrangement of boxes in the time suggested and without being seen. Surely it would have been more believable to have them just grab a pre-built column from behind a truck, scurry out and slot it in to narrow the gap while Tanner did a quick U-turn and pulled his mirrors in?
While I am happy to excuse a bit of scripting for the sake of a good gag, responsibility rests with the producers to make sure they do their bit reasonably well to keep the viewer under at least a partial 'reality spell'. It's not the viewer's job to stick with the pretence no matter how badly it's done. The 'detour through small-town suburbia' was a good idea, but again not that well orchestrated