845 is TECHNICALLY a sealant. And what is the point of a sealant if the coating over the sealant is still there???
With 845 over top nothing will penetrate to the sealant so the sealant is not really necessary.
I'd just do a spray was after every wash just to add shine
845 is great stuff and has been around a long time. Can't say a bad thing about it.
FWIW - its a blend product by all indications, so TECHNICALLY it would be a polymer reinforced wax, not a sealant.
As far as layering goes, direct from their own website:
4. Can Collinite Last Step Products (LSP’s) be used in conjunction with an alternative brand sealant?
Between producing, pouring and shipping, we’ve yet to conduct testing with all the sealants out there (too lengthy to list), so this practice cannot be formally recommended. However, sealant + Collinite LSP layering is a common method among Collinite aficionados. Call us with specific questions or check out reliable online forums with inquiries.