I start my washing procedure in the winter months when it's salt on the road with a solvent based degreaser. And when that has worked in I spray over an alkaline product with ratio of stronger than normal right over the degreaser. Why do I do this is for desolve tar and roadgrime and salt as much as possible. Then I rinse it of and go with an 2 buckets wash with carpro reset. I do not have a ceramic coating and at the moment my protection is gyeon wet coat. Before I had Ultima paint guard plus and I always top it of with a qd that has a strong protection for a qd. This is the go to procedure for dd in Sweden for us detailing hooked people. The degreaser we just put on from bottom of the car up to a bit under the windows. Because you don't want to get it in inside of the doors or in the chanels under the windscreen. That can eat away of the rust protection inside the car and don't spray it in the wheel wells too. In the rest of the year the degreaser is used when needed if the paint is being rough to the touch and if you see tar spots on the paint. The alkaline product is used in the rest of the years as a prewash with a milder delution to get the bugs and roadgrime of. Maybe you have a prewash that is alkaline based in the US? I don't see much of that in stores there. I use most my foamcannon to prewash with it. This is an aggressive way to wash and most waxes won't hold up to it. But sealants and coatings are strong and can put up to this. Of course it will tear on them but you use a product to fill the damage after with a product in the family of your coating or sealant. And you often have a topping on that take the hit. My believe is that you save you self from the need to clay. And as you do go with ironx sometime when needed.
One product a forum member told me contains a bit of both is this.
https://www.autogeek.net/meguiars-car-wash-plus.html
Test this 2-3 washes to clean the sides of the car and see if you can revive the coating. Maybe do a test spot were it's really bad and see what happens. I can look for products that is used as a prewash. Carpro tarx works great to remove tar and some other dirt but it's a bit pricey and there is maybe more economic products that desolves tar. When I think of it a citrus based prewash would work as the alkaline product but a bit easier on the protection. There is cause of useing this two different based chemicals and that is it removes different kind of dirt and grime. I just wanted to share how I and many others do in Sweden. We don't have problems with water restraining and to use chemicals on ours property. And this don't work to do in the sun as it can not dry. But for you who lives in parts of the country it's real winter with snow and then they put salt on the roads can use this method. And if you have access to shade areas or places you can work inside or covered. It's also important to have access to pressure washer or a strong water pressure from the hose to rinse well.
