I'm just in the process of replacing the shocks and springs on my car, one thing that has really surprised me is the level of corrosion on various parts/bolts under the car. I removed the rear shocks and started to dismantle the bump stops, the old ones were a horrible mess, holding water like a sponge. See the pic below for a comparison between the old and new bump stops.
Because the old bump stops were saturated with water the damper rods were badly corroded, you can actually see where the rod is eaten away by rust and leaking badly.
After changing over all the parts needed to the new dampers all i need now is for my springs to hurry up and get here!
Here's a pic of old and new dampers.