2013 P85+ - OptiCoat everywhere, then on top of that full-body Xpel Ultimate. Very happy with the results.
2016 P100D - Full-body Xpel Ultimate everywhere except parts of the B pillars, where two new hi-def cameras live. Ceramic Pro layered over that (extra layers for the B pillars); Ceramic Pro makes the surface too slippery to put on first, the Xpel won't be able to stay on top of it. Only a week or so with this combination but so far very happy with the results.
Apart from my own below-average driving skills, there is just too much crap in the roads and from up above to live without the Xpel on this expensive vehicle that requires aluminum auto-body shop skills and prices. Compared to aluminum body work, I've saved quite a bit of money by replacing pieces of Xpel due to rips, snags, tears, light scratches, small impacts, and so on, that otherwise would have marred the paintwork or even made a small dent.
I strongly recommend the Xpel. I've never been 100% sure what the chemical coatings really do for me in the real world as opposed to what the manufacturers tout, but obviously I've paid twice now in the belief/hope that something good is happening (OptiCoat, Ceramic Pro).
Alan