Ouch! sounds a nasty cleaning process!
Re the solid black, yes can tell the difference (well I could anyway) I bought my current mk5 in Black also for same reason, I clean mine myself, AutoGlym gives a top shine and if you put in the effort you get a fantastic deep gloss with the solid paint (sounding like a detailer now!), having said that a few times last winter took it to one of them imo washes when it was too cold (plus thinking of ice on the pathway next moring from washing day before ouch!).
This time I almost went for the white or the Blue, but then saw a black 5 door with 18 inch monza's and went wow, want one!