NEVER take your car through a brush car wash no matter how many signs say "soft brush". That is the same thing as a "light gun".
NEVER wax your car without having first washed, dried and polished it thoroughly. Avoid cleaning your car on windy days and in areas where there is lots of dust and dirt.
ALWAYS use clean terry towels for drying. Better yet, us a chamois or liquid absorbing towel to remove surface water and dry with microfiber cloths.
AVOID parking your car in the open or uncovered in areas where there is contaminant emitting industries, power and chemical plants or refineries, etc.
THE BEST way to remove contaminants and some light scratches is to apply CLAY-BAR to your car. Be sure to read instructions carefully and use the proper tools. A random orbital buffer is suggested but if you have never used one, read everything you can about what NOT to do before you do.
MOST buffers are good. Some are better than others. You don't want one that runs at too high a speed. There is more chance of putting scratches or mirror-swirls in the clearcoat.
AFTER CLAY-BAR, wax and polish your car with a premium wax. I prefer ZYMOL.
SWIRL AND SCRATCH REMOVERS DON'T WORK AND ARE A BIG WASTE OF MONEY. IMPROPER USE OF RUBBING COMPOUNDS will result in highly noticeable cloudy spots in your finish.
The problem with the finishes on most cars are from improper washing and drying, contaminants in the air, improper application of waxes and polishes, especially in direct sunlight.
Taking your car to a car wash where a used cloth can be used to dry your car or where low-paid "detailers" who have little or no experience and no attention to detail for your car in mind is like turning your car toy over to monkeys and paying them to mess up your car.
Simply, PEOPLE cause most of these problems. Not products.
Now the larger problem - dealerships.
You would think that you could trust a high-end car dealership to prep your car properly and with the utmost care. NO. Not when everybody is operating on the cheap these days.
Most of them contract their detail out and you won't find the same two people working on the crew day to day. The dealership has no control over who these independents hire. My own personal experience is near a horror story with absolutely no acknowledgment from the dealership.
Simply, since I have a pre-owned car, they believe I had every opportunity to inspect the car before I drove it out and held the insinuation that I could have done something to the car after I purchased it -- even though I called it to their attention the Monday following my Saturday purchase.
There is never complete peace of mind with having someone detail your car, so unless you run them through your own approval process with background checks and references, etc, learn how to prevent these problems before they begin and DO IT YOURSELF.
If nothing works - you can try wet-sand but again, find out WHO is doing it and how long they have been doing it. Ask to see some of their work. It's expensive. You will expect satisfaction.