My S3 has developed a really annoying noise which sounds like it is coming from the back of the car on the passenger side. It all started after i changed my back disks and pads not long back. Everything went ok on the change over and all was ok for a couple of weeks. I then started to notice a sort of tapping sound which is sort of random in occurance but if you use the brakes it goes away this even works if you put the handbrake on 1 click whilst moving. I have since taken the brakes apart and checked it over and it all seems tight and as it should be. The only thing i sort of thought it was is there are 2 bolts on the caliper which i can only describe a sleeve bolts eg one side is a hollow tube and the other is a bolt so you hold the sleeve with a spanner whilst tightening the bolt with another spanner. Anyway i bought 4 new bolts from audi (they wouldn't sell me the sleeve part of the bolt) and fitted them and all seemed ok for about 50 miles and now the noise has come back. Asking for any ideas for a solution please.