Well my Octy failed the MOT on a slight nearside front disc judder and a rear offside wheel bind. Very annoying as lot long ago I spent £200 getting new discs and pads at the front and having the rears cleaned up. So how do you unbind a rear wheel and is why would a brake disk judder after 4 months?

Depends how good the mechanic was who did the brakes, not very by the sounds of it. Judder will either be a brake snatching, or more likely a warped disc, or mechanic didn't clean the hub face properly and you have excessive disc run out (should be less than 4 thou).

Binding, handbrake not fully releasing, or partly seized caliper. Brakes are easy to do BADLY, it takes a fair bit of skill to do them properly.

Or they might not have been bedded in properly and have glazing on the disk surface - it doesn't take a lot to cause judder. The rears are known to have problems sticking, when changing they really do need to be cleaned properly

My rear caliper was binding, ended up having to buy a new one. I seem to remember seeing this happening to a few 1.8T cars with what I can only assume are the same rears.

take it back to the garage that did the brakes. binding could be that the sliders on the caliper are seized or even the piston. did you not ask the bloke who did the mot his opinion?

Well the car has been in to garage and it has had a service, cracked hose repaired which was making the car run lumpy and both rear pads, shoes and calipers replaced as they had locked on and would not release. All this set me back a mere £504. I cant afford to eat now but should now fly through the retest. Did feel a lot better to drive, maybe because the rear brakes weren't locked on

That's another month of not been able to afford a remap