I get something similar when braking gently/medium at motorway-ish speeds, but not 30/40mph.
I find a double application stabilises it, no idea why. Just lift off very briefly and reapply. :Confused:
(standard PF discs, front pads virtually new and genuine Audi)

Ah the joys of an auto box, front brakes take a hammering coming in to roundabouts / junctions and then get held on the brakes until it's clear to go. This localises the heat from braking in the areas that the pads are in contact causing discs to warp.

Not saying this is the case for all of you as it obviously itn't. But if you have access to or have a lathe put the disc's on and check them for ture.

TOP TIP, USE TIP.

or stop a little earlier and let the car creep forward for a bit, lets that extreme heat out the brakes.

Right, car back from a big service and a look at the shakin' brakin'.

Bad news on the service is that there's a spark plug stuck! :( Going back whilst I'm away in Spain for a week for a soak in WD40 and another try to shift it.

And the brakes - hmmm. It had new front discs and pads just before I bought it. It now has another set of new front discs and pads! Not fitted properly, apparently, something to do with shims not being removed and cleaned out when the pads were fitted. Result is a much lighter wallet, :-( but beautifully smooth braking :).

And after the service, the car feels brilliant! Quieter, more responsive and generally good all round. :love: Thanks A4 Audi.

Well the mattress will have a little more give now with that large wad of cash removed :ROFL:

Yes, the gardener says it's much more comfortable now. :)

do you mean the mattress or just that hes more comfortable now he's got a large wad of your cash? :p