First, I apologize if there is already a thread about this. I searched a couple threads but I didn't exactly know the right words for this. But anywho, About a week ago I came outside and noticed the back of the car was sittin on the wheels. Cranked it up, compressor kicked it and brought it back up. No problems for about 2 days, now its just about every morning I come outside for work and the rear is sittin. At least 50% of the time, maybe more, once I shut the car off, it'll slowly sink down. Is this a problem with the compressor, the ride sensors, or an electrical issue?