ChevyZ76

Just noticed the other day when I was driving down the road on Sunday. The MPH alerts seemed to keep coming on, and I have it turned off. Then I turned on the lights and it said that I had a tail light out, which it was. Then today I turned on the lights and it said that I had a license plate light out, which it was. But then I rechecked it when I got to school and the lights were all working. Never changed any bulbs out. I also noticed that when I press the unlock button on the key fob the the gas filler door would open. Any ideas? Would a vag scanner help me narrow down the problem? I was looking at the vag scanners...which is a good one? Thanks

2005 A4 B7 Quattro 3.2