Normally I'd put this down to the discs but I've changed them for good quality Bosch ones and the problem didn't go away.

There is an advisory on the MOT "Nearside front lower suspension arm rubber bush deteriorated but not resulting in excessive movement" and the same for the offside.

Could this be causing the vibration? It's quite severe when braking from 50/60mph to the extent that it makes the steering wheel shudder. Vibration is arguably worse if braking with the clutch pressed than if left in gear longer.

Any advise appreciated.

Yup, I'd say that those are almost certainly the cause of your issue. I had the same thing and swapping them out for some powerflex's sorted it.

I had similar issues on mine till I changed the front wishbone bushes.

Just off to get mine booked in for front wishbones today for exactly the same reason. (other threads here suggest doing the arms is simpler than just the bushes alone)

Forgive my ignorance (I know nothing about suspension). Are the bushes mentioned in my MOT advisory wishbone bushes or something else?

I know nothing either but for two new arms, including the bushes and ball joints I've just been quoted £250... however up on the ramp for a looksie and there is a bunch of other issues so I suspect my Octy is dooooooooooomed.

Forgive my ignorance (I know nothing about suspension). Are the bushes mentioned in my MOT advisory wishbone bushes or something else?

Yes.

I know nothing either but for two new arms, including the bushes and ball joints I've just been quoted £250... however up on the ramp for a looksie and there is a bunch of other issues so I suspect my Octy is dooooooooooomed.

£250... ouch! I am tight, so I borrowed a mates press and changed them at home. New bushes were about £15/side (2 bushes per wishbone)

Well the parts (arm+bush+ball joint) are about £90 ish+vat (for the pair) on the garage system, hours labour for each, track check bit of rounding.

or about £85 inc vat on well known internet / local shops with a bit of discount, so if I was in any way technically competent I could do it. But I'm not.

Thanks all - I had to do wishbones on the other Octy when I bought it so not really a surprise. Will get it booked in.

Finally got around to getting the wishbones replaced. £180 all done with tracking adjusted too. Vibration problem seems to have gone away touch wood. Garage was adamant they were fine though - perfectly MOT worthy. To be fair though, they are not specialists with the cars but are well priced and workmanship always excellent so I will let them off.

Thanks for all the help with this thread,