Probably service washes that cause them marks, kids aren't as bad at washing as dealerships I've found haha
. Dealership washed mine in march when it went for an mot after it hadn't been washed all winter and was obviously covered it grit and other shit, it was and still fucking is covered it swirls and other marks, cba to correct them as its a daily and its literally the whole car.
Anyway scholl s17+ on their orange foam pad if you are using a machine.
If by hand people have had good results using gtech p1. Personally only used menzerna polishes by hand and the effort and time it takes to achieve what you want just isn't worth it.