need help on driving simulator

hy all,
I am (still) messing around with my driving simulator.

Again I encounter serious problems: my car-cockpit is a uv map; in addition to that I made some warnings. They should be off when starting and I want to switch them on/off with a keystroke (e.g.: acc warning on/ off with A) which I can not figure out how to do.
Of course I want them display correctly (they are in front of the cockpit but they appear behind in play mode).
Could someone please help? THX in advance

You can find the file (5mb) on:

http://www.futureinterfaces.at/blender/GEProblem63.blend

Parent the planes(signs) to either the camera or the car-cockpit. That should keep them in camera view at all times. As for having them disappear at start and reappear when triggered, set them with a visible/invisible actuator.