07 Grand Prix GXP 77,800 miles. I had an alignment performed at town fair tire in mid April at approximately 74,500 miles. They didn't do a perfect job to say the least. I am avid about protecting the front end from hard impacts example.. driveway exit and entrances - railroad tracks- speed bumps - pot holes and bumps- curbs ..etc... So I've gone approximately 3,000 miles and the car feels as though it should be realigned again. Maybe I have parts that are worn and need replacement?..Can anyone comment on which parts may need replacement as it seems the alignment should have lasted longer. Since I am so careful to protect the front end from any road impacts I suspect parts may be worn. I have driven at 60-70 mph on a 2 mile long perfectly straight stretch of smooth highway holding the steering wheel perfectly steady and after about 1/3 mile the car begins to slowly veer off the straight heading I've intended.. at about 1/2 to 3/4 mile it is enough to have to correct its path.. I've tried it all kind of ways to determine if it'* the tire pressure, road ,speed, wind etc.. I've even tried stradling the lanes and the problem seems independent of the road itself.. What could be the issue here and which parts might be suspect? Thank you.