i was wondering the same thing.doing some research, i see many that recommends this two parts clear.
https://www.amazon.com/gp/product/B0043B7UQY/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1i ordered a can for experimenting, and hope to get good results.
will report as soon as i have some (results that is

)
2 things to take in consideration.
1. being 2 parts clear, it is more toxic than the 1 part, so you will need to use proper protection.
2. the can is good for 12 hours once the two parts are mixed, so it's better to clear multiple projects at the same time.
as i'm doing my first steps with car part skinning, i'm trying to decide if to clear coat or just buff the epoxy.
i got the XCR resin so it should have some UV protection qualities. not sure to what level.
not to hijack this thread, i will open a separate on on the subject.