If it’s supposed to be automatic (no key press), then an overlapping volume is the way to go, why not. If you start in the seat, you can check what is around, which trigger box you’re in, the nodes mentioned above.
Besides that, you should probably setup some flags for the player so they know which seat they’re in. Since you start in that seat, you can set that flag to be the default. It can be a simple integer value, or a Map variable which could help with communication. There are really too many options.
There was also a tickbox for that behaviour (check overlaps on Begin Play or whatshername) somewhere but I can’t recall where - I think I had it explained by @ClockworkOcean?
edit: I thinks that’s it:
