Brakes squeaky

Have a Superb and its only got 15k on the clock and I am noticing

squeaky rear breaks when stopping at lights at low speed. Had a

quick look at the disks and they seem a lot thinner than the

ones up the front. So two questions:

1. Are the pads suppposed to be much thinner ?

2. It is likely after only 15k that I need new pads ?

Just want to be a bit educated when I drop into the dealer

as I only have 1k on its since I bought it from them and it

had a full service before I took delivery.

Thanks

Kevin