I don't think this age of A4 has rear pad wear stuff, my wife's 2015 VW Polo 1.2TSI SEL has zip all brake wear stuff - now that really is "progress"!
Edit:- I'm sure that I've spotted that the front pads for my wife's Polo are cheaper if you buy the ones that have a wear sensor - then snip the wires off, now that is proper progress!