RS 4 front suspension knock on rebound - HELP?!!!

[RJKflyer]

Six months ago my RS4 leaked a pool of oil from the OSF shock. The dealer replaced a 'union'.

2 days later, horrendous knocking from front and rear over smallest of bumps. Car to dealer by Audi recovery - "do not drive".

"Central valve" replaced and system "repressurised".

One month later, a knock on rebound developed, seemingly from both front corners - just like what you'd get on a MacPh strut when the top mount bush wears out. Going over a sleeping policeman shows it clearly - loud knock from front end on REBOUND (i.e. as you come OFF of the bump not ON to it).

Dealer diagnoses leaking shock (this time OSF), ad replaces OSF, NSR shocks and central valve.

Just the bloody same, despite all the guff about through road testing and signing off and complementary hoover of the carpet. Two minutes with the Master Tech and he says "definitely not right".

But they seem unable to work out what this is. It's going to end up being "let's just swap stuff out until it goes away". Meanwhile I'm off of the road and the car will be rubbish by the time it's been dismantled half a dozen times.

This is the best car i've had, but if either it's not durable, or the dealers can't maintain it , I am going straight to BMW.

Can anyone help me, and stop me having to do this?

Audi - where are your experts...?

[RJKflyer]

Sorry, the second dealer action was NEAR side front plus OFF side rear, which is odd as it was not the 'diagonal' originally involved. WHich means the WHOLE system has failed in various places.