The transmission. When the car decelerates, the transmission goes down several gears, and when I go to accelerate, the transmission shifts hard with a sudden bang. When this happens, it shifts into another top gear. This cannot be good for the transmission. I have taken it to the Ford dealership, and had it plugged into the computer. This seem to fix most of the problem, but not all of it.
We love the car. It is beautiful and we get lots of great comments about it. It's comfortable on long trips, plus the handling is pretty good also.
The gas mileage is anywhere from 23 MPG to 32 MPG. The trunk has lots of room also.
The car is not the quickest thing on the road, but it still has enough power to merge into traffic, and the six speed transmission helps the car to do just that.