Support fast winter wash?

Hello guys, a question to the care professionals who have been asking me for a few weeks: My last car was a 12 year old, black Volvo combi with almost 300,000km on the clock. It was clean or dirty, came irregularly into the washing machine โ€“ or not and was all in all a pure everyday vehicle. My new car has been a white convertible for a few weeks now, it’s all a bit different. Apart from the fact that the fabric canopy is something new, a white car i of course, you can see it all much more with a white car than with a black one. Now I actually wanted to avoid our local, partly already very old washing facilities, because these partly nevertheless very rough with the car and wash more by itself. Our local self washing system offers however no really great cleaning possibilities like Snow Foam Lanzen o.รค. but only the classic brush and a high pressure cleaner. Hand wash is evenly In winter, however, I am not allowed to do so, but actually too much effort. Actually, the car should only be freed from salt and dirt every few hundred kilometres and not be highly polished. Unfortunately, washing at home is not possible, which the municipality forbids. So my wish would be to find a product that I can use on the self-washer after the vehicle has been sprayed. For example, from a spray bottle. Because the high-pressure cleaner alone brings the dirt nic I don’t want to scratch over the car with the completely finished foam brushes. Is there something like that or do you have a recommendation for me? I’m not a “pet fanatic”, but it’s of course annoying if the road dirt pulls up to the windows and after the scratch and this barely recognizablely thin soap spew variant from the high pressure cleaner the car still looks the same as before.