Here is an excellent article on this subject. Though it is for winter cleaning, it still fine for summer. The video is well done and explains the process.
How to Safely Wash Your Car in the Winter
by Marc Harris & Jacob Bunyan
Trying to keep a driven car clean in the North is impossible. The good news is that by using the right products and techniques, you can periodically have a clean vehicle without stripping your wax or inducing swirls to your finish.
First, let’s examine the two most often used ways of having a clean vehicle in the Winter months. Drive-through “Soft Touch” car washes will leave your vehicle’s finish swirled and dull. In addition, I’d recommend anyone to stay away from places that use questionable mystery products. Touchless car wash bays use harsh products to chemically clean your car without physically touching it. Not only are these products bad for your plastic and rubber over time, they’ll strip off any wax or sealant you still have on your finish. Sacrificing your protection for a few days of having a clean vehicle doesn’t add up in the long run. Both of these types of car wash bays can quickly strip your protection, and both have been known for adding “beading” agents into their rinse water so that owners have the illusion that they still have wax or sealant on their car. I’ve seen how these products work in person: you begin rinsing down a vehicle and there is obvious and prevalent beading, but after a gentle wash and rinse, all water lays flat. The harsh cleaning chemicals keeps owners with dirty cars happy while the illusion of protection keeps more discerning owners thinking they’re good to go.
Luckily there are better and safer methods of Winter car care that you can use during these ugly pre-Spring days. I’ll discuss my favorite method: The Great White Winter Wash. This is a traditional two-bucket wash adapted for Winter use, when most of us can’t use our frozen water sprockets outside of our homes. While most won’t have the time or energy to commit to this type of Winter wash, it is a better and safer alternative that allows owners like me to keep their sanity every now and then by having the cleanest car on the road.
(2) Five Gallon buckets
(2) Grit Guard bucket inserts to be used in your buckets.
(1) Car wash shampoo; your favorite kind. I prefer high quality shampoos like Dodo Juice Born To Be Mild or Chemical Guys GlossWorkz.
(1) Wash mitt. Sheep Skin wash mitts are my all time favorites, but this could even be a microfiber towel if you choose. Just make sure it is a paint safe material and clean.
(2) Drying towels. Microfiber waffle weave style are my go-to towels for drying.
(1) Quick Detailer, Spray Wax, or Spray Sealant. My personal favorite is Dodo Juice Red Mist Tropical as it is very slick, glossly, and has given me a month of protection by itself. Optimum Car Wax or Opti-Seal are other great choices and I like.
(2) or (3) High quality microfiber towels to be used with your Quick Detailer, Spray Wax, or Spray sealant of choice. The DI reTHICKulous towels are perfect for this.
(2) or (4) Latex, rubber, or nitrile gloves. You only need two, but I like to have an extra pair handy in the event I get a rip in one or more gloves.
(5) to (10) Dollars in quarters.
Last but not least, you’ll need to search the net for a Gamma Seal bucket lid. These are attachments that fit onto your 5 gallon bucket to give it an air-tight seal.
1. After successfully installing your Gamma Lids onto your 5 gallon buckets, place the Grit Guard inserts into the buckets and fill them with the warmest water you can stand in your bath tub or laundry sink. Warmer water breaks down grime easier than cold water, and will help to keep you warmer while you work. One of your buckets will be all water, the other will be your water+shampoo mix. Follow the direction for dilution. Some car wash shampoos dilute 128:1, others such as Dodo Juice’s Born to Be Mild dilute closer to 800:1. Proper dilution saves product and gives you the most effective cleaning power. Close the lids and secure your buckets and supplies into the car (clean plastic bags like shopping bags or garbage bags can be great for transporting your microfiber without contamination).
2. Drive to your nearest Do It Yourself car wash bay. Here in metro-Detroit, they’re often sparsely populated. Most bays don’t want people to bring their own supplies as they don’t know what types of chemical you’ll be pouring into their drains, and they don’t want you to hold up their money making business in the event of a line beginning to form in the event you’re moving slowly. Every bay I’ve been to has the same signs, but I’ve yet to have a problem.
3. Begin with giving your car a thorough rinsing with the DIY bay’s pressure washer first. This should be done using the “Rinse” cycle water.
4. Using your buckets and wash mitt, perform a traditional two-bucket wash on your vehicle. In very cold weather, you’ll likely need to rinse the car once more half way through to avoid significant ice build up.
5. Rinse the vehicle to flush dirty water and shampoo residue off the finish.
6. Lightly but quickly dry the vehicle with your waffle weave towels. Don’t worry about light water residue: your Quick Detailer, Spray Wax, or Spray Sealant will take care of any remaining drips or streaks.
7. Apply your favorite spray protection product. Keep in mind many of these products aren’t designed for such cold climates and will therefor work much slower. Don’t forget your windows, head-lights, and tail-lights!
While your results might not last a long as they do during the warmer months of the year, the few days they last will buy you some time of sanity after seeing your baby trashed for most of the season. Even better, you won’t have a horribly swirled and marred vehicle come Spring! If you want to see an example of how this can be effectively done, please check out the following video I made with the help a highly talented local photographer named Steven Pham. Steven gave me a hand in documenting exactly how I used this exact process to clean my girlfriend’s vehicle (Thanks Jessica for the loaner!). The results speak for themselves:
I hope this helps some of you fellow enthusiasts take better care of your vehicles, and if you have any questions on my method or process, please ask in the comments.