Does anyone know or have a opinion on how long a set of bilstens should be expected to last ? I have purchased a 93 vert and was going to replace the shocks with a set of bilsteins. But upon closer inspection found that it already had a set on. They are very dirty and grimy and look as though theyve been on awhile. I didnt think that they came stock so someone before me put them on. Should I think of replacing them or would I be wasting my money?