Milltek Sport has come up with two sport exhaust system for the 2013 Audi RS4 B8 to make driving this fast and practical German estate car a bit more fun and exciting. They offer a primary cat back and a non-resonated system, so you can have either a loud bark, or a dignified growl.

Fabricated from the highest grade austenitic stainless steel, Milltek’s system for that RS4 uses the latest ‘ValveSonic’ technology, featuring active valves that work seamlessly with the OEM vacuum system. The most clever bit is that they’ve integrated this into Audi’s Drive Select system to activate the valves at different RPMs.

The RS4’s engine has a high-revving nature, which makes it perfect for a valved system. You get the usual rumbling noise at low RPMs, but when you step on it the valves flick open and you get a motorsport-like soundtrack. Here’s a quick demo of Milltek’s system:

Priced at £1672, this system fits Audi’s stock bumper and tailpipes.