Thoughts on satin/flat paint jobs?

[thorsen]

I have an old Audi Quattro that I use as my "snow car" and summer cruiser. It's a smaller 4 door sedan, and I'm thinking that I want to paint it in a satin/flat/matte finish. I'm not worried about cost of supplies, resale value, or what other people think. I am concerned about longevity of the finish, maintenance concerns (can you wash? doe sit need to be waxed?), and "hiding" (ie - does a satin black hide more dents that gloss black?)

Does anyone have any practical experience with a satin/flat/matte paint job?