GX470NC

I have just purchased a 2004 GX470 with 55,000 miles. The ride seems very bumpy/springy. I can make the car bounce by pushing down on front fender. When going over a speed bump in our neighborhood the rear end seems to not take it very well. Maybe this is the normal ride for these models, but that is why I am posting. If anyone can give me any insight or suggestions before I bring it to the dealer please let me know. Thanks