I ordered EBC Redstuff DP32270c brake pads (rear) from FCP Euro and on their site it said it is confirmed fitment for GLC63s (red calipers) but when I try to install it the pads appears to be a different size and shape from stock. I looked at different sites selling the EBCs they also said it fits, so what gives. Need some advice here.

Our rears take DP32314C. I just ordered these myself. What you ordered are for GLC43 platforms.

I just looked up the part number you gave and there it is on FCP Euro! Thanks for much for your help.
Btw, any reduction in the dust it generates?

I’ve only had them on for 25 miles or so. My GLC63 is my weekend toy. I installed EBC’s because whatever cheap junk the dealer installed before I purchased were squealing horribly.

I finished installing the Ebc DP32314C 2 days ago and so far so good, as far as dust levels are concerned they seems to be very little dust but then EBCs have a bed-in coating on it that is to reduce dusting for 500-1000 miles so I'll keep checking in on it.

Few months ago swapped to Giro 2pc and ebc red pads in the back. Less dust and no squeaks too.