Black is the worst to keep clean. But is looks awesome when it is done right. I also use two buckets, microfiber towels (I think I have about 15 or so), QD all the time. I never wash it in the mid-day sun, usually early in the morning. I wax it with Meguires Gold Class or NXT paste wax and use the clay bar when ever I have time.
My wife gets pissed at all the time I spend on the car, but she sure doesnt complain when she gets to drive it. (not often)
Just remember that spending a little extra time and money now will make it last a lot longer.
I just sold my 93 SHO, Black with Black interior. With the exception of a few stone chips in the front, the guy who bought it could not beleive it was the origianal paint. He said that was the main reason why he wanted it.
GL and KEEP IT CLEAN