@Tubby23 - since you brought it up just want to run it by you:
For the Amazing Race the in thread challenge would be to figure out which of the 5 linked maps (using the "share" or whatever the "play with friends" method is on geoguessr) is the right one to play. Then it would be a combination of "first to finish" plus "best score" minus "first doing incorrect maps" or something to figure out who wins/loses for the day.
Does that sound right? I
think it's a 5 game limit per day, so that would let you do it without needing to buy it.