Based on the promos I saw last night, which were pretty clear when seen live, it looks like the ROADBLOCK or FINAL TASK takes place in an area that is divided into perhaps four areas by wooden fences. Each area is dominated by a globe face: Africa and Europe for Rachel; North and South America for Nick. In the background there seem to be objects associated with episodes in those areas: In Rachel's shot there seem to be a mule,(ep 1) UTurn sign,(ep 4) and a small boat (ep 6)all of which could be associated with Ireland, Amsterdam, Burkino Fasi, Lithuania, and Croatia. So is the final task some kind of memory test?
In one of the promos there is a scene of an excited Ron and Chris jumping with joy. But look again this is a pickup from a previous ep (Chris is wearing a pink tank top). So could it be that the editors are playing games and the shot of Rachel holding the ROADBLOCK clue with a soulful face might be a pickup from a previous ep? TK did the roadblocks in eps 1, 3, 5, 7 and 8. So could this be Rachel watching in one of these? perhaps ep 3 when TK is milking the camel?