First off, let me explain why. I know, at first glance this seems like a weird request, "why would you want to sit on yourself", but the thing is, over time avatar seats have been doing some wild stuff. For example, there's a few teleporters over on Gumroad and Booth, where you can set enter/exit locations. But due to how avatar seats currently work, you can't use them, but others can.

Allowing players to sit in their own seats would open the door to even more unique interactions, toys, gadgets, and more. An example of what could be possible is bringing your vehicle to use in racing/driving worlds.