Guys, so if y'all struggling with this achievment just join a pvp playlist and be patient it might take some time. If there is like 1-3 people in a lobby leave the playlist and join a different one, or you can try rejoin the same playlist but it may just throw you back in a same lobby. So when you found a lobby with 4-6 people in there im pretty sure if you just wait the rest of the lobby will join. If lobby is not full just leave before the playlist starts. The catch is that you don't need to actually complete the playlist with all 8 players, all players must complete the 1st race without leaving it. And finally if you manage to complete 1st race with 7 other players (or just full lobby) just finish the rest, it doesnt matter if someone leaves the playlist. When you finished the playlist (any place) you will get that achievment.