The use of a foam gun is the best way I know of so far to minimize, if not avoid ,any wash induced marring altogether. For me it's more fun to do than inspect for and polish out marring ( more clear to remove) later on.
I use it like this:
Foam gun set on strongest mix ratio, foaming in one hand, a good sheepskin mitt in the other, the car already foamed down, spray the foam gun on a small section at a time. Where the foam is flowing over the paint, very gently whisk the mitt across the section. As needed, rinse off the mitt and/or dunk it in a bucket of clean water, move on to the next section ,smaller for best results (to be very extreme, use multiple mitts dedicated only to certain sections or parts of them )
Basically, the constant flow of soapy foam over the paint is not only helping float dirt away, its acting as an ever flowing lubricant when you're using your mitt. I really like using quick disconnects and shut offs with my hose and I've ditched the trigger part of the foam gun and just have the mixing end attached directly to a cut off switch to a quick disconnect to the end of the hose
When you're all done, simply disconnect the foam gun and use the free flowing water fom the hose to rinse and help dry.
Oh yeah, the foam gun can come in quite handy to use while claying not to mention no more mixing car wash in a bucket.
