Hugo

Hi all, I am new on here, recently purchased my first Audi, it's a 2006 A3 S LINE 2.0 TDI. The brake pads warning light is on, checked pads all round, front are fine but the rears are bare, I bought a set of Bosch rear brake pads and they advised in the description that they are "prepared for wear indicator", but when received there was no sensor inside, just the 4 pads along with 4 bolts. Please can someone advise further as to whether there is even a sensor on the rear brake pads, or how I am supposed to reset the warning light once the brake pads are fitted? Is there something I need to do whilst fitting the pads or do I need to buy a separate replacement sensor etc? The other warning light is for the number plate light bulbs, I have however checked the numberplate lights and they are both working, can anyone tell me why this warning light may still be on and how I can reset it? Thanks in advance!