Audi has been testing the upcoming facelifted version of the 2011 Audi S4 Avant on the Nurburgring in Germany. This the the first time the car has been seen out in public.

Like all of the latest-generation Audi models, the facelifted Audi S4 features a softer and slimmer front grille and headlight design. The S4 also gets a revised front bumper layout, incorporating a sportier, more aggressive look.

As far as engine performance goes, no details have been leaked yet. The 4.2-litre V8 might make it’s way into the S4 range, handed down from the current RS4. A revised supercharged V6 could also remain under the bonnet. We’ll have to wait and see.

Interestingly, the test mule spotted on the ‘Ring also appears to feature a full roll cage set-up inside the cabin. From some angles you can see the windscreen bars trailing down the A-pillar at the front.

Either Audi is truly punishing the car on the track to get the most out of it or the company is planning to release a GT3 version, although it’s not very likely.

Reports say the finished product of the Audi S4 facelift will debut at the 2011 Frankfurt Auto Show in September.