Hi guys.
As a professional vinyl fitter & having done so for last 27 years & also as a time served vehicle refinisher for the previous 10 years, You need to understand that vinyl is a soft material that is easily marked even by dust! Cleaning your car using modern chemicals is a no no! As is using pressure washers ANYWHERE near vinyl stripes or graphics. Only way to avoid scratching your stripes is to hose the car down thoroughly before washing with soapy water by hand a panel at a time starting with the roof & working your way down, rinsing from top to bottom as you go otherwise you will be spreading the dirt with the sponge, cloth or wash mitt all over your precious paintwork & stripes, which in turn causes tiny (or large) scratches.
Imagine polishing an ebony table top with a scouring pad, That is what you are doing to your paintwork!
Just to give you an idea how sensitive vinyl is to being marked: When fitting stripes the cleaning instruction labels are cut off my microfibre cloths as they can scratch the vinyl!!!!!!!!!
Be careful guys (& girls).