I have a 2003 Grand Prix Gt silver with 78,500 miles on it. I'd rather have a 06/07 gp gt, but I'm not sure how much value I would get out of my car. The body is extremely clean, and is mechanically all stock. It has a new pioneer radio, hid headlights, black air dam, and new grills. The problem I have (where I need your help) is that it has an oil leak. I was told it was the rear main seal and the oil pan gasket. The thing is, I only need to change the oil or top off the oil every 4 months. So for those who change their oil every 3 months, they wouldn't even realize the leak. At the end of the day, it still has a leak, even if it's a minor one. What does this do to the value of the car? I haven't found the 06/07 gp that I want, so I'm not motivated to sell, but it would be great to know what I could get for my car for when I do find the next gp I want. The car has also been in the same family since day 1. For a n/a grand prix, I think it's pretty rare to find a car in this kind of shape and miles (especially with it being through 12 harsh winters), but people would rather have a gtp than a gt (like me lol).