What, and break the wonderfully harmonious ambience of your typically multi-cultural British suburb? This will never do.. we don't dare mention such responsibilities as safe driving in this day and age.
If it's a one-off I would let it go. Yeah it can be frustrating but so can lots of things.. near me we always get huge vans holding asian food and clothes and god-knows what else, parking on blind bends both sides. The council does nothing despite the obvious hazard and this goes on all the time. In your case the driver may have been helpful if approached..I'd let it go but that's just me.
If any driver feel frustrated in this situation then think about how it feel for cyclist every day.. it is like this every day for cyclist, you car driver take up road and in big city car everywhere holding cyclist up. And cyclist more at risk. Every day it is critical mass of cars in this country and cycles suffer for it..
What do you expect from a Mercedes driver?