I've been hand waxing automobiles for 35 years and never had one fade. All Meguiars waxes have sun block, according to the manufacturer, and I've used Turtle Wax with excellent results on past cars. I've been using Meguiars Ultimate Paste on my Mercedes E350 for 10 years now and it still looks showroom fresh, even after baking in the hot Georgia sun. I agree with the user above who applied two coats when the paint feels dry; I've always used two coats of any wax. For extra shine, I apply one coat Ultimate Paste followed by one coat liquid Meguiars Carnauba wax.
How often to re-apply? Anytime the glossy feel is gone and the paint feels dry. The time between wax jobs depends on how much sun, rain and washes you perform. If the car never leaves the garage, the wax protection will last indefinitely (I stored a car for two years and the finish never tarnished). Don't use a car cover, because I've had them stick to the surface and dull the paint, requiring a compounding. I use a generous amount of wax and work it into the surface rapidly while it's wet; the petroleum in the wax itself "washes" the paint without scratching. I wash the applicator sponge thoroughly with dishwashing liquid after half the car and wax the bottom half of the car last, washing the applicator as it gets clogged. Buff with microfiber clothes and don't rub with heavy pressure.
The biggest hindrance to a perfect shine has always been achieving a perfect wash. A quick wash of a dirty car, then wax, often seems to seal in a micro layer of grim that is dull and extremely difficult to remove (because the wax is "protecting" it). I've found it really pays to soak the car with the commercial wash available in self-serve car washes for at least 15 minutes, preferably with warm water, followed by a power rinse. I then re-wash the car lightly with a sponge and soapy bucket. I understand why you choose only touchless car washes, but once you've power washed, don't be afraid to use a sponge to remove that last, very fine dirt. Do not use a clay bar as a matter of routine, because I've read it will wear down the clear coat over time. I've soaked my paint with WD-40 or Goof Off Professional to loosen road tar and bug spots. More recently, I use L.A.'s Totally Awesome cleaner on very stubborn spots. If you do happen to have a layer of grim sealed into the finish, I've removed it after a regular wash with six ounces of ammonia in a small bucket of water with a sponge (be sure to rinse immediately). Finally, don't use well water or wash the car in direct sun, because you'll get very stubborn water spots. Always dry the car lightly with a towel after a wash.
Don't compound the car routinely. It's too abrasive and will wear the clear coat.
