Whatever you're using (and this'd include *wash* media too), don't do long, sweeping motions where you go a long ways uninterrupted. If (more like *when* ) you get something trapped between your [whatever] and the paint, a long motion will result in a long scratch. If you just use short, interrupted motions any marring will be a short little scratch, that won't show as readily.
Whenever I see some 4" long bit of marring (let alone anything longer!) I think "eh...crappy technique...just asking for trouble"
If waterspots are a big issue, I'd consider a CR Spotless or something like that (no, I haven't tried mine out yet

). Even a water softener will offer a big improvement.
I'm still getting most of the water off with the AirWand, and then getting the rest with WWMFs, usually spritzing some QD at the same time. (Regulars here know that I can no longer do the sheeting-rinse due to my spigots/pressure.) I'm not even using my CWB for windows, as scratches in glass are forever and I know that *someday* I'd get one, even as careful as *I* do my washes.