I'm close to needing new rear tyres on my (W203) C350. It currently has Pirelli Cinturato P7, which were on it when I bought the car. A couple of MOTs ago, I had the front tyres replaced with Continental Contisport Contact 5, for no other reason than the Merc garage I was at didn't have replacement Pirellis, and suggested these instead.
So it seems reasonable to get the same Continentals on the rears too, but looking around the web it seems that although people seem to like them, they apparently wear very fast. I already have them on the front, though...
Anyway, any thoughts appreciated
PS the speed rating for my car is W, but the Continentals they put on the front are rated Y. Should I match the Y rating with whatever I put on the rear?
PPS front spec is 225/45 R17 91W, rear is 245/40 R17 91W
So it seems reasonable to get the same Continentals on the rears too, but looking around the web it seems that although people seem to like them, they apparently wear very fast. I already have them on the front, though...
Anyway, any thoughts appreciated

PS the speed rating for my car is W, but the Continentals they put on the front are rated Y. Should I match the Y rating with whatever I put on the rear?
PPS front spec is 225/45 R17 91W, rear is 245/40 R17 91W