I really love the AMG CLK63 Black Series, I've spent a fair bit of time in that car, it's brilliant.
A very good friend had some serious work done to the gearbox, engine and software by HWA in Affalterbach (or AMG Studio, can't remember) at some eye watering cost but I hear it was worth it. Actually, I very much miss that car, haven't been out in it for yonks
Haven't been in the SLS Black Series yet, probably in Spring time unless it's been shifted by then