Hi Simon (and welcome to TM!)
When I got my Aero (Series 1) , it had new front pads fitted but they made a real racket - squealing like a stuck pig!
From memory, I changed them to EBC Red Stuff pads.
The Ref. was DP3036C,2000-2004 Yr. - they were approx. £90 plus - I don't know if these will fit a Series 4, but I'm sure EBC will have others.....?
I think the 'feel' of the brakes was improved, albeit not massively.The noise was certainly a lot less! A side benefit was that there is now hardly ever any brake dust on the wheels.....
You can check out the original post here -
Aero brake padsPlus,I think Simon at SiFab also has Mintex pads available.....
James