touchy warning lights

I have a 2001 Beetle GLS and it seems that nearly every time I take it in to have the oil changed the dealership has to run diagnostic codes and turn off some warning light on the dash. I'm due for an oil change in about 1,500 miles but my air bag light is on (it's been on) and yesterday my check engine light came on. My husband seems to think that the car is just sensitive or may have poor wiring. I don't know much about cars but I know that I have never had a problem like this in other vehicles I've owned. I love everything else about the car and would love to buy another one but not if it's a common problem. I need some HONEST answers. I don't trust most dealers to give me the an ernest response. HELP!