I TuffStuff all knobs to remove grim/hand lotion from them. You'll have to get the area around the buttons/knobs as well because it will typically transfer there too. Don't forget the steering wheel with this stuff. Don't over-saturate the radio of course, but a little TuffStuff on the controls isn't going to hurt anything. ONLY exception to this, Audi Touchscreens seem to be more sensitive to cleaning agents. Be careful with those. Just use water, no soap on these.
I use a 1" wide paint brush cut to half length to dust out vents. I've tried using brushes made specifically for detailing but the ends always curl/fray/add more debris from it falling apart.