I just discovered like 3" or 4" of water in my trunk surrounding my spare tire. I had a flat during horrifically cold weather, weather was 10 - 20 degrees for one solid week. Called OnStar. They sent someone out one night, in abominable cold. Lucky I was at home. I went out to open car etc., and attendant discovered the spare tire frozen stiff in water. I was shocked. I seen that my trunk carpet was a little wet but didn't think much of it. I have no idea how long this has been going on. It is awful. This car has major water problems. First the headlight issue and now the trunk. I am disgusted with this car.