Griott's Garage Interior Cleaner followed by the Griott's Interior Protectant. Yes, the interior protectant is expensive but my bottle has lasted for about 3 years since you don't have to use much and it is low gloss.
M3Driver, As often as you tout Griot products I'd think you'd spell it correctly! Mostly good stuff, if not a tad overpriced: http://www.griotsgarage.com/
Everyone has a favorite product. I like 303 aerospace protectant . http://www.303products.com/shop303/index.cfm/category/1/303-aerospace-protectant.cfm
Vinyl. Nailed it in one. Same here. Low sheen, low dust attraction, 9+ years and the dash looks like new. And there must be a dozen others that work just as well...it's just what I happened to switch to, when my prior favorite became unavailable.
I also use sunscreens in my window. It not only blocks the sun when it sits there, but the car is cooler as well. I live in S. Texas and the summer sun is relentless.
OK I did receive my Griot's Interior Protectant this PM so I went right out to the garage and tested it out on my dash. WOW! I didn't realize that my dash was that dirty. The stuff is pretty nice to use and leaves a nice finish without the greasy look. I'm happy!
I usually clean with either Meguiar's D103 (10:1), or Meguiar's Quick Interior Detailer, then dress/protect with 303.
I've found a better price for the 303 products... http://www.detailedimage.com/ and the best part is this protects your dash against UV!