I bought my GP from an elderly chap with only 23k miles and 7 years old. It really been driven, so the transmission was a little sticky for a few thousand miles, but loosened up. I've had no engine problems until recently, terrible engine knock when cold. Suspension has been excellent, never have had to replace anything down there yet. Transmission is starting to become difficult when cold, won't shift into drive except when in 1st gear. The radio was crap, but relatively easy to replace with instructions from Crutchfield. Driver side seats seem to deteriorate fast, then you're sitting on springs. Gas mileage goes to pot when you run the engine hard. Difficult to perform engine maint.
When you step on the gas, the engine ROARS to life and you feel like you're in a muscle car! Pretty impressive power for such a big sedan only a V6 3.1L.
Better, more comfortable seats. Better gas mileage. Make it easier to perform engine maintenance, especially the oil filter.