Recently purchased a very clean 96 coupe with 60K miles. Have started noticing a bit of a vibration as speeds between 35 - 65, particularly when encountering bumps in the road. I think the tires/wheels may need balancing but am wondering about the shocks. It has Bilstien shocks. Are these the type of shocks that come with the vehicle new ? What is the best way to test shocks to see if they are in need of replacement ? What are my best options for improving the ride , not much of a hot rod'er just like cruisin the Houston Autobahn.