In my experience, dealers usually do not prep the cars and apply paint protection correctly, it is all about do it as quick as possible. I was offered paint protection on a 4 year old car for £300 (from Toyota dealer), when I asked will they tend to all paint chips, strip old protection and do the paint correction before applying ceramic coating, the answer was no, we will just apply it on top. A friend of mine used a ceramic coating specialist and it took two days to prep and apply on a brand new Ford Kuga.