We have only one major problem with the car. It does not like to start when it is cold. The car is finicky that way.
Shakes very badly above 80 miles per hour. Gets worse the faster you go. Handles badly around turns and power steers. The car hesitates when you floor it and shifts at the wrong times. The car is a little big too. It handles like a big boat from the eighties in some situations.
You really need to take the car in to a mechanic and have them look at the problems you are having. Those problems are known issues and can be resolved if you take it to a mechanic. Good Luck. PS. I have a 97 LHS with only 63xxx miles and I really love the car.