1999 Buick Lesabre Car Hops

We bought this car used and it happened as my husband drove out of dealership but we thought it was the bumps from the turning lane and ignored it. It only hops if you step on it as you go from stop. (If I was at a stop sign, trying to squeeze in to traffic or in a hurry and go to the floor with gas.) Obviously, I am still fine as we got it at 108,000 but when it does happen it is frustrating. I've just learned to be patient but was wondering what needed to be fixed or replaced. Love the car otherwise. Very dependendable and economical.