spacers lowering springs

Hi lads, I'm about to order some 30mm lowering springs, and 10mm & 15mm (would 15 & 20mm be too much?) spacers for my Audi A4 Avant SL Black Edition 2013. I want to give it a more aggressive look. I have the 19 inch Rotors, just wondering if anyone with experience can tell me if I'm heading for...

Bought 15mm front and 20mm rear spacers and got 20mm h&r lowering springs just waiting on them getting delivered. Will they change anything in the car system like the speedo or anything like that also what about warranty is this more likely to cause problems that the car will need fixed under...