ok firstly, any time you get a new car, when you trade it in, you loose money. That's the cost of driving. Cars depreciate. It's a fact.
Secondly there are lemons and horror stories for EVERY make of car you can think of. And usually you hear more about the bad than the good. If you want any car to last you a long time you need to take good care of it. Do regular maintenance and don't drive it too hard.
Now, i have a 2006 G6 GTP. and i love it. it's alot of fun to drive. faster than most people think. I drive pretty hard and the car has not given me any problems at all. I had a leaking issue but that was a known problem with the 2006's and it was fixed under warranty. I also had a blown speaker that was fixed under warranty..but that was my fault. lol. I know have 77,000 km on it and have changed the Front brakes at the start of this summer. That is literally all the work this car has needed.
I run synthetic oil in my car all the time and don't drive it in the winter. (I live in a cold climate where we get snow and therefor salt on the roads)
These cars are really fun to drive and I have had plenty of cars to compare to. Enjoy