There's some dishonest editing this episode. We're shown that the best way from Domme to Toulouse is on the A20, while Quinton/Mattie took the (smaller) "D49... [staying] on it the whole time". But neither the D49 in Dordogne nor the D49 in Lot (the next department over) lead to Toulouse. In fact, when they're shown later in the episode navigating small villages, the footage is really just them getting out of Domme.
Quinton/Mattie must have been on the D49 for just a short while trying to get to the A20. I wonder what put them that far behind then?
...
For Marcus/Michael, part of the confusion entering Toulouse is that there are overlapping highway designations at that point. While the highway sign only shows "E80 / E9 / Périphérique intérieur" going left and "E72 / Périphérique extérieur" going right; maps would more prominently show A62 going left (which Marcus later says he doesn't want), and A620 going right instead.
If teams understood French / the French highway system, they would also have found that "Périphérique intérieur" refers to "Ring road, going clockwise" and "Ring road, going anti-clockwise", which would have been much clearer when matching where they are to their maps.
