Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
If this is the usual problem of them splitting then second hand is rare as the seals split. I'm currently waiting to replace my split drivers side one (am on holiday so can't do it yet)
Buying new is the best way to go and make sure the surface is thoroughly clean to get the best adhesion. They come with the adhesive on them.
There are a couple of threads on this on clio197.net as them splitting is a common issue.