usually, the rears should be good for 30-40,000 miles for pads. I replace the rotors because its hard to find a shop of just cut them, and they are usually rusted and a pain to remove, stuck to the hub. I got the powerslot rear rotors that are cad plated. I replaced the factory rotors on my 2003 last year. so I got 60,000 and 4 years out of them.
My new front EBC sloted rotors wore out in less than 8 months. I heard this moaning sound and it was the pads ripping out the cross veins of the slots! they were gone on the inside and outside were 80% gone.