gettina nasty knocking noise from rear brakes when applied in reverse only happens on initial application then disappears until you go forward then reverse again .very off putting you would think that you hit something any clues

Hi!

I also have a knocking noise when I start reversing. It took several months and pointless garage visits to figure out by myself (the idea inspired by Fabia owners discussing the air ventillation of their cars) that every time I switch to reverse AND start rolling backwards, the air ventillation system automatically blocks the way of incoming fresh air because in this situation it wouldn't be fresh air but exhaust fume!

This blocking probably happens by closing a flap and this makes a knocking noise.

You'll hear this knocking noise only once while You're staying in reverse as this flap keeps the way of incoming air blocked. When You switch to forward gear again AND start rolling forwards, the flap opens without any noise.

After this when You start rolling backwards again You'll hear a knocking noise.

I also believed that it comes from the brakes but no.

Just try it the following way:

Switch the ventillation system to inner circulation mode and after this switch to reverse and set off slowly. If You won't hear any knocking noise, then it is the same situation as mine.

alrite m8? did u fit ur new rear dics u said u were gona get? remember u sayin yhey were squeelin last year. there's a meet in april, r u goin?