Dub....> "bad boy bad boy whatcha goin do when they come for you..."
On the plastic and rubber parts of the rack I spray it on and let it sit/soak for a long time, on the towers, end caps and flaps I usually do it overnight. It gets kind of dried up but I spray it again lightly the next day, then start working it with a rough shop rag. Rubbing really REALLY hard takes off the oxidation & crude off the plastic (including the nasty stuff inside the end caps).
By the time I'm satisfied with the dry oxidized layer being removed, they are basically "dry" so no further "wiping dry" is necessary. And I can tell they've absorbed a ton of the 303 because they have a totally different moist look, so I like to leave them that way, not rubbing them any dryer. And they're not sticky or tacky so it works fine.
I just lightly wipe the aluminum cross members after I've washed them. It leaves finger prints on metal surfaces like these, so I end up using a rag to grab and pack the cross members.
Same with the plastic & rubber engine bay bits...just wipe down with the 303 damp rag, and leave 'em that way.
I think the "wipe dry" instructions MAY be so it doesn't collect as much dust...I can see people complaining to them about that.
Thanks KAT, good info. I'm also sorry to have dragged you into a conversation that is more than likely going to draw out a lot of comedy over the next little but here. HAHAHAHA.