<---13yrs experience in automotive finishes. Caring for paint is fairly simple.
Your clearcoat is essentially a plastic coating. Most anything that touches it, will scratch it to some degree. The key is to minimize contact with anything, ie a pressure washer works wonders.
Assuming the paint in question is of excellent quality, these are the steps I would follow to bring back to life, the most overwashed, scratchy, dulled out, black paint job on the planet.
1. Spot "wetsand" prominent scratches, the grit you choose is dependent on your buffing "skills" and compounds involved. I normally use 1500 grit and have no issues getting out the sand marks.
2. Heavy cut, white wool pad with heavy cut compound. This will get rid of any harsh surface wear, it will bring dull back to shiny and rid the car of most tar/sap contaminants. Because of the heavy cut nature, there will be many swirls left behind.
3. Heavy cut foam pad, with mid-grade abrasive compound. This should remove any and all abrasions left from step 2.
4. Very fine foam pad, with highly residual compound. This is the final step in polishing, it will smoothen out everything and give it that wet appearance.
5. Wax the vehicle, using a clean sponge wax applicator. The higher concentration of carnuba, the better outcome you will have. Use a debri free microfiber towel to remove the wax, by NO means use any terry cloth towels, tshirts or dirty underwear.
6. Using a pressure washer, get all the cracks and crevices. This should remove any extra compound, hopefully you've taped any rubber moldings that may degrade with contact from the previous buffing. I'll use a half moon sponge to go over jams, etc.
7. Dry the car, using a SHAMMY and a SHAMMY alone. Water blades are fast, but I just don't trust them on a freshly finished car.
8. When possible, use a compressor and air tool to blow out cracks and crevices, following up with a shammy.
9. Invest in some spray wax. Once the car is dry, go over with a quick spray wax using a microfiber towel.
Maintenance would be touchless car washes, followed by a blow off and a spray wax each time.
There is absolutely NO reason anything other than a microfiber towel should ever touch your vehicle while it is dry. While wet, a clean sponge will cause the least amount of damage, NO TOWELS TO WASH OR DRY YOUR CAR.
Doing step 4 bi-monthly will keep your car looking better than new.
Anything more than what I said is useless. I would be surprised to witness someone who's better at automotive finish maintenance than I am. Do not attempt to use a high speed buffer on your baby, unless you know how to use it.. Practice on the family van, that's how I got started. There are no magic in a bottle products, they are gimmicks. Products don't really matter, if my steps are followed and you're using something similarly described.
P.S. Wheel shine is garbage, attracts debri. Use vinyl conditioner on your tires, they stay dry, black and new looking, without splashing grease up and down your ride.