My car wash of choice is run by a Chinese guy who is anal about how a car should be washed/protected and he offers a 48 hour warranty, if the car gets dirty in 48 hours, he washes it again for free but that doesn't extend to redoing the interior.
He jet washes the car first to remove dirt, then some kind of detergent is manually applied before an automatic contactless car wash rinses the car and blow dries it. I have learned a lot from him, for example the first thing I do at any other car wash is check the staff, if they are wearing rings, watches, belts, necklaces they get a lecture from me and I leave.
He put a ceramic coating on my last car from new, a Benz E class, I paid 9,000 baht for it and he also did my daughters Kawasaki Ninja 400 for free. Every 3 months he topped it up for free. I wash my car every time it gets dirty, sometimes 2 or 3 times a week. Ceramic coating helps with swirls, but it doesn't stop them, it doesn't stop stone chips/scratches at all. If I remember right he used Kinsho Japanese Ceramic coating, I did some research and unsurprisingly, it came out as one of the best. After 2 years he told me it was wearing off because the car was washed so often and wanted to renew it, I passed because I had plans to change the car.
On my current car, a Porsche I went to another guy here in Chiang Rai who fitted Rhino Self-Healing PPF. More expensive at 65,000 baht but if you want to preserve the paint, nothing else comes close. You can remove the film after a few years and the paint underneath is still new. Fitting it is a PITA, it's quite thick and it probably took him 4 or 5 attempts to get it right. It will peel and it's important that the installer offers a warranty to replace any section that peels, typically tight bends. There are 2 ways of fitting PPF, computer cut or manually cut. Computer cut will make the pieces applied slightly smaller than the cars panels and at the edge of each panel there will be a lip where the film is slightly smaller than the panel, typically 1mm. Over time you will get a black line there as dirt accumulates. Manually cut, the film will cover the panel, wrap over the edge and impossible to tell it has film unless you look under the panel (door, bonnet, trunk etc) where you can see where it finishes. I paid extra for self-healing PPF, you can scuff it up with a wire brush and the scratches disappear in the sun. On reflection, I wouldn't pay the extra for that. I did have to pay 6,000 baht for where a motorcycle tore the film with a foot stand, and a large piece needed replacing, fortunately the paint work was undamaged. The self healing film appears to stop swirls in the film as it repairs them, but whether it's worth the cost, I'm not sure. The finish with self-healing PPF is not as good as the original paint, on sharp bends in the bodywork, the film is stretched and if you look closely you can see it. My intention is to remove the film after a few years to either renew it with a colour change or sell the car. If you have an expensive car and want to get top dollar for it when you sell it, or you drive fast and want to avoid stone chips (I don't) then I'd say it's worth doing. The main benefit is when you remove the film, the car paintwork is still brand new.
Some people even put ceramic coating on top of PPF, I don't think it's worth doing that, certainly self healing PPF will never swirl.