i've done sent my previous ride for autodetailing before. even spent like RM6.5 k on a coat guaranteed (and leave car there for 2 days) to still show water beading for 12 months. unfortunately, i still needed to get it 'touched' up at 3 monthly intervals.
what i can say is that, if you want to do coating - have a good reason for it. normally that reason is to satisfy something personal eg treating it like a hobby or you are particular about not having swirl marks/micro scatches etc [detailing stuff]. to keep the paintwork in factory pristine condition always is not economical and ...frankly, unless you are surrounded by detailers - most cant tell the diff.
why ? from a car point of view (my personal view also), it's pretty expensive and at the end of the day when you sell your car - you get zero value for it. in fact you look after the car for the next owner.
anyway, i adopt a practical approach now - just have it washed regularly, polished and wax at set intervals.
Fighting the elements is a constant battle - if you have the time and resources and the passion - do indulge in it, it's pretty satisfying.
Otherwise, as much as we love our rides, practicality is more sustainable