Hi, we just purchased a 2003 Eclipse. It has a 4 cyl. Engine with 15,000 miles. It has an automatic transmission with the sport-tronic computer whatever it does ! Anyway, the transmission stutters when shifting, mainly when it is under acceleration like getting on interstate. It acts like it is shifting too fast and it has to downshift again because it is under a load. Sometimes it does it three or four times in a row. Around town it is doing the same thing, but not quite as erratic. We didn't notice it during the test drive (of course!), Only after we got onto interstate and the car got really warmed up. The fluid is very clean and full. I hope somebody can understand my explanation and help. Thanks for your time.