The green and red signs indicating the entrances and exits to the racetubes are currently single-sided. If you get behind them, they are invisible due to backface culling. Please add a back face to them, so that the entrances and exits can be identified from behind.

+1

Why would you be going down a racetube backwards?

(I can think of one reason at least, playing devil's advocate here)

It's more of "Which side do I start from?" thing when you jump in to the sector.

Yeah, that was when I originally noticed - when I warped into the sector I was behind it, and didn't know which opening to aim for. It is also relevant for the maze, if you aren't sure whether you've found the exit or just gone in a circle. I think the exit has a force field effect and the entrance does not, but I could be mistaken. Being able to see the signs through the glass would be more obvious, at any rate.