If you intend on using both NXT and EX-P, I believe that you should apply the NXT first as it contains some cleaners that will strip off some/all of the EX-P. Once you apply EX-P, you can follow up with subsequent coats after a cure time. If you'd like you can top the NXT/EXP combination with carnauba, like Natty's, Pink Wax, etc. However, once you do that, you can only apply additional coats of carnauba as the polymers won't bond to the carnauba.
Do a search and I believe that you will find numerous threads on combinations with NXT and topping polymer sealants with carnauba. You will have literally thousands of combinations for different colors, etc.
Good luck finding a combination that you like.
