Bad Struts?

Essentially the same as bad shocks. The bounce test isn't good enough. Use the weight of the vehicle to force them into compression and then watch for rebound. e.g. zip forward and hit the brakes hard so the car weight compress the fronts, then watch to see if it wags up and down. Some are stiffer than others and will only go down, bounce up, then settle to position. Some may go down, bounce up, then go down a *very* little and then settle *up* into position...this would be a vehicle with a normally soft suspension. The rears can be tested by backing up and hitting the brakes. Also look for cupping on any tire.