I have 24000km (15000mil) on my P5 and my rear brakes appear to be worn.

This doesn't seem normal to me.
I don't drive hard.
I've never driven with the e-brake on.
My last car I didn't change the rear brakes till 100,000km (60Kmiles)
I got an appointment at the stealership on Friday to check for premature brake wear. But I wanted everyones oppinion before I bring it in.



This is a pic of the wear indicator on the reardrivers side. It's about 2mm away from the disk. The passenger side is even closer.

The front brakes look new.

 

if anything....your front pads should go out first...seeing as how they do most of the work. and I have gone as many as 95,000 miles before needing to change ONLY the front pads before.

 

Since it's the inner pads of the tread, I'd assume it has to do with the E-brake. I know you said it's not on, but maybe your cable is stuck somehow. Try driving the car for a bit, and feel the rear inner side of the discs. If it's hot, you most likely have a stuck e-brake.

Just a thought.

 

Ok,

went to the dealer to get em inspected.

Turns out this is not the wear indicator. This is a spring/clamp that helps hold the brake pads on the caliper.

So the brakes are fine.