I had a black merc - but as has been said, tends to be a fairly common colour colour and a nightmare to keep clean (wonderfull after a wash tho)
now have a white audi TT - really stands out, you get noticed, but... if a fly sits on it (and usually pukes up on it) its VERY visible
I've now ordered the 370 in black rose - who knows how this will turn out
these are the only photo's I've found of the GT ed in this colour