In summer, 1 coat of sealant, and one coat of wax every 3 weeks or so. Sometimes more often than that if I got some new products that I can't wait to try out.
In winter, 3 coats of sealant before winter really starts, and wax every month or so for the remainder of the season.
I usually go with a layer or two of either Blackfire or Fourstar every season, and MAY add a trial layer of carnauba on occassion in between seasons....My own feeling is Polys are every bit equal to carnaubas....with the exception of unsurpassed durability...
Now that I have black car, I always end up going back to carnaubas, even though at times I top sealants with carnaubas. Just something about black paint looking deep enough to swim in that makes it worth it.
Sealant alone that was applied to a max'd prepped surface. I rather repair blemishes than hide them. All the natural depth, wetness and richness is now protected long term. Found no visual enhancement after topping with a carnauba worth the potential decreased durability, the extra effort, and removal to add another layer (gotta do something ). As Patrick stated most high sealants mimic carnauba results with emphasis on Prep, without the dropoff or need to constantly QD to renew the oils.
I've been using AIO/SG topped with P21S or S100, but am going to try EX-P (or EX-P+) for my wife's navy Jetta and UPP for mine over AIO, and possibly topped with carnuba. I want to see the results of the sealants first.
I had been using AIO+SG+S100 on my blue-silver TSX. About six months ago, I switched to AIO+SG+UPP. I doubt I'll go back. Love the way UPP looks on my car.