Those rotor alloys come in various fitments for audi A1, A3, A4, A5, RS3 etc, each with a varying width and offset.
Just make sure you get the correct ones.
Some of the replicas come in slightly different offsets too.
You'll need the A3 fitment:
Part no: 8P0 601 025 BS
Width: 7.5J x 18
Offset: ET54
They should fit, even with 30mm lowering, you may have to do the 'fender mod' (also known as
screw mod), but dont think it will be needed on a 30mm drop.
Someone else will hopefully confirm that.
Hope this helps.
Jas