Audi S5 Persistent front end problems!

[cps13]

Hi,

I have a 2007 Audi S5 which seems to have a gremlin sat in the front suspension/running gear somewhere.

In the last three years it has had:

2 sets of discs and pads due to them being warped
2 lower arms (each side)
1 steering rack (about 18months ago)

I have now got a vibration in the coming from the front under braking and the garage have said the discs and pads are warped, there is slight play in the front wheel bearings and there is slightly play in the steering rack.

I believe the car has been lowered by a previous owner, but I cannot find information on this, apparently it has RS5 springs on it. The garage is saying that this may be the cause, that the lowering is putting undue stress/loads on the running gear. What do people make of this?

Thanks