My 2c and worth no more than that.
For all of my cars, whether daily hacks or special ones, I take the following approach:
Once paint is protected (see below below), cleaning routine is:
Pressure spray/rinse with water
Foam spray (which is just an attachment that goes on the pressure gun, with foam on it)
Pressure spray rinse with water
The above steps take 5 to 10min and take care of 80% of the debris on the car.
Then, panel by panel apply a 'Quick Detail' spray and wipe clean. The word wipe is the key here, not rub or polish in a circular motion. The idea is to take a microfibre cloth and wipe in one direction, in one motion. If you look at this surface of the microfibre you will see there is dirt in it. Can't use that surface now as you will effectively be dragging dirct across your paint, resulting in micro scratches and swirls. So fold microfibre and do the same trick again....and again. Each microfibre is effectively good for either 8 or 16 wipes, depending on how you choose to fold it. Place dirty microfibre in bucket, pick up a clean one and go again.
This sounds convoluted but it's actually quite fast and you are essentially letting the microfibres do the work. Do not use a sponge (they retain dirt). After you've fininshed with the car, the microfibres get a hot wash in a washing machine, dried out & ready for next time.
Start with 20 microfibres....you will be surprised how many you use. The same microfibres, with the same quick detail solution can be used safely on the interior.
I use the following products for the 'foam' and 'quick detail'. If you buy in bulk it's muuuuch cheaper and products have a forever shelf life.
Foam - https://www.zas.com.au/product/854/3d_pink_car_soap_38l.html
3D Pink Car Soap 3.8L | ZAS Automotive | Go To Shop
3D Pink Car Soap is a high concentrate shampoo that can be used as both a traditional bucket wash, or with a foam lance as your foaming agent.
This product can be used as snow foam with an applicator or it can be put into a bucket to use for a 'two bucket wash' if the car is too dirty for the above cleaning approach (ie you've been on a 1 week trip etc).
For Quick Detailer/Cleaning/One Wipe method I've used:
HD Touch, 3D waterless wash, Meguirs QD, Optimum Car wash
3D Waterless Car Wash 3.78Lt - VG Auto Paints
Waterless Car Wash is a revolutionary soap-less car wash that cleans any automotive surface. Waterless Car Wash cleans, and protects without using water. It can also be used on chrome, glass, dashboards and door panels. Just spray-on and wipe-off with a clean soft microfiber towel. Waterless car wash formula will pen
I tend to buy whatever I can get my hands on in a 4 to 5L size as I do a lot of cleaning. The brand is less important than the approach. In principle, you want to get the dirt off the paint....without touching the paint 🙂. So the less invasive the solution and approach, the better (ie snow foam and then a waterless wash/QD spray and wipe). Next best is two bucket wash and then if you have items truly stuck in paint there is the hot cloth approach (microfibre in hot water, place on stain/dead bug, leave 3 min then wipe area with QD spray & it should come right off.
You can buy harsher chemicals (bug & tar remover etc) but the general rule is....try the least invasive first.
In terms of protecting the paint, the general process is:
Clean (as above)
Rub entire car with clay bar and lubricant (QD)
Apply polish or pre wax/protectant solution
Apply layers of wax or protectant.
Note that polishing is the gentle abrasive process used to rub out any small scratches or imperfections. Waxing or coating the car is the process of applying the protective layer. A product that says 'polish and wax' cannot do both well 🙂
The paint correction and protection process, by hand, on a car about the size of the 944 will take about 3 hours and then 30min for each additional coat of protectant. The clay process basically takes the paint back to a clean surface (the clay lifts impurities such as dirt etc from the paintwork). The paint is then ready for preparation/correction (whether by hand or machines) and then protection (wax or chemical coating or ceramic coating).
The time you invest in the clay/polish/wax routine will be returned ten fold by the ease of cleaning afterwards. Dirt will literally wipe off the paint (or even better, hose off).