I purchased my G6 is May of 2009 and have had issues ever since. This particular issue occurred when I was driving home from work one day, had driven for approximately 20 minutes, started crossing a bridge when my dash lit up like a Christmas tree. The car starting shaking, the oil temp gauge was on red. I managed to make it off of the bridge and into an auto parts store. Took a look and all my antifreeze was gone, but it was not leaking under the car. I thought maybe this could be a bad thermostat, so we filled the antifreeze reservoir, and took it in to the dealership. Turns out, my engine block was cracked, after only 19,000 miles! This had caused the antifreeze to flow freely into the oil, etc. After a week of dealing with this they replaced the entire engine. Very disappointed in GM!