You along with Luffy’s crew is a pretty big car, Nami stole it for the road trip. It has of course the drivers seat and the passengers, so 2 seats in the front. There are 9 other seats with rows of 3. Obviously Luffy isn’t trusted to drive for obvious reasons, Zoro would fall asleep, Brook isn’t heavy enough to press the pedals, and Chopper is too small to even look at the road, so they obviously not driving. You get to choose the arrangements of where people sit! Also you don’t have to make your own character, you can be one of the StrawHats. :D have fun!

(You don’t have to do this but this would be my arrangement if you need inspiration:) Robin driving with Brook in the passenger seat. (Bc why not) Chopper is in the first row in the middle of Usopp and Nami. Franky and Jinbe are sitting in the second row with an empty middle seat, and I’m stuck in the back with Zoro and Sanji.