It's being made somewhat the same way, but i'm able to make them faster from the bedroom. If by buggy collision you mean the missing collision or that vehicles clip thru it easily, the 2nd one is a problem with using giant collision meshes. However, since the floor is split up into a few collision meshes, that shouldn't be a huge problem.
Yeah that's basically what I meant, I have an idea... why not load collision meshes separately?
Say you load the bedroom model then there's a script that tells it to load the required collision meshes.
That way you can split it into smaller parts that work better.
