I am about to order new rotors/pads for my 2002 a4 and was going to go with a Zimmerman xdrilled coated rotors and akebono ceramic pads but I am wondering if there is a specific pad recommended for xdrilled rotors. Also wondering if this is the time to go all out and order new calipers for a step up to a 312mm rotor. I am becoming a cheap old man and think that the step up in size would be overkill as new rotors and pads should make for an almost new ride given the current rotors are original! Also concerned about the sensors and shims on the pads-never dealt with them before and cannot see any wires without taking clipper off. Worried that original callipers are soon to need repairs/replacing as they are original with 180000km(112000m) Any thoughts ASAP!

 

I cannot address ALL of your concerns, but, I can tell you that you need to make sure you break-in your new rotors IAW manufacturers instructions, or, like me, you WILL experience cracking around the holes in your rotor-face(s).

If you're going UP in rotor diameter, make 2xdouble (yes, I know that's actually 4x) sure they will fit inside your wheels, when mounted. Don't just do teh maths, do a test-fit!