We bought this car in 97 with 40,000 miles on it. It now has 150,000 miles, mostly highway, but we live on a dirt road and it has seen some rough trips! I love this car - it has been very reliable and the interior is so roomy. Two car seats and kid's stuff in the back is no problem, I've squeezed three in the back, but wouldn't want to do it very often. Only problem we've had (and it cost a lot!) is at 98,000 miles the transmission went out. Mechanic said it's very common on the Lumina and Grand Prix.
The trunk has two curved arms that close it and they take up a lot of space! Also, can't pop the trunk from inside, must use key.