I just purchased a 2006 Mazda6 S GT with 58,000 miles. There is some lag and power loss between gears. When going up hill it hesitates for a couple of seconds before accelerating. When going down hill it sometimes feels like the car has a engine brake. It makes for a unpleasant drive sometimes. It feels like I have to fight it to make it shift correctly. I'm taking it to the shop on Tuesday to have it looked at but I have a feeling this is going to be a ongoing issue. Does anyone have an idea of what's going on? Any info would greatly be appriciated!