Create car interior with portal

Godot Version

4.2.1

Question

Hello! While developing my multiplayer game, I added a vehicle - BTR. I’d like to add an interior to it, but adding it to the VechiclesBody doesn’t make sense in terms of physics (the car will be unstable) I decided to add a room below the plane and use portals to add entry/exit and windows. However, the portals were removed in Godot 4. Also, my game is multiplayer, so I need something optimized, even if not with a good picture.