I usually enter a charity show in June. I don't win anything.
I go over the instruments and horizontal surfaces in the interior with a microfiber dust mitt like
https://www.speedcleaning.com/Speed-Cleaning™-Microfiber-Mitt_p_83.html. Then I vacuum everything until the vacuum won't pick up anything else. Don't forget the trunk.
I use saddle soap and a microfiber cloth on the seats and dash. Once a year or so, I'll apply Johnson's was to the seats.
Put a trash bag over your motor and wash and wax the underside of your hood. Then get the engine compartment. Don't forget the bottom of the trunk lid, though you can't really use a hose for much.
Vacuum off your motor as best you can. Don't wash the motor unless you have compressed air ready to dry it immediately. If you don't have compressed air, you might be able to get by with a damp cloth or wipes like
https://www.stp.com/product/cleaning-engine-degreasing-wipes/.
Clean your exhaust tips. Then polish them with a good metal polish.
Before you wash & wax the exterior, wash the painted surfaces on the inside and bottom of the doors. When you rinse the outside, it should rinse away most of the suds. I like Turtle Wax car wash, but any car wash concentrate should work. Wash and dry your car.
If you have tar on your car, bug & tar remover works ok. WD-40 takes off a lot. The STP wipes work well. Mr Clean Magic Erasers work pretty well too.
Wax it. I like
Nu Finish b/c you only use it once a year, and it works great. I guess ceramic product are the hot, new product. I'll try them when my Nu Finish bottle is empty.
Once your car has been waxed and it's sat dry for a day, use a preservative like Armor All on all your plastic, interior, exterior, and under the hood. Few things are more annoying than trying to apply a preservative on wet plastic.
In 2022 some people mistook my 08 for a new car that was the raffle prize.