Clear Bra (Paint Protection Film, PPF, etc.) can be an amazing source of protection for your paint. However, it is important to remember that it is a form of protection first and can look great as a byproduct. It can weather, scratch, peel, etc and look bad, but it is protecting the paintwork underneath which is the most important part.
With that said, there are many methods to help protect and even correct clear bra to keep it looking as good as possible.
Cleaning Methods:
Cleaning clear bra is no different that cleaning normal paint. Use gentle shampoo (i.e. Chemical Guys Maxi Suds) and make sure there is plenty of lubricity.
Protection:
This is also just like your paint and you can use sealants, waxes and even coatings to protect the clear bra from UV rays that could yellow it and add hydrophobic capabilities. If the vehicle has exposed edges of the clear bra (i.e. half hood) ensure you tape off the edge too not allow for wax to get under the edge, which is extremely hard to clean after. (p.s. half hoods never look good but that’s a topic for a different day).
Correction:
Correcting clear bra is possible, but not at the same level as paint. A very light polish (i.e. Menzerna 3800) is all that should be used and making sure you monitor the heat of the panel is crucial as to not burn the clear bra. Many times with clear bras the only way to correct them, is to remove them. They have done their job in protecting the paint against all of that damage and now it must be removed and replaced.
Damaged Clear Bra
Old Clear Bra
Bare Paint