After great success with our Audi TT RS Rear Sway Bar, we started development on an affordable, performance-minded rear sway bar upgrade for the B6/B7 Audi A4/S4/RS4 Quattro.
While the OEM RS4 Rear Sway Bar Upgrade is very popular, we feel that it leaves a bit to be desired in terms of performance. Combined with the rising price of Genuine Audi parts, we will soon have a much better alternative available. 
What we ended up with is a bar that's adjustable from 100% to 124% stiffer than the stock B7 Audi RS4 Rear Sway Bar.
Diameter:
- Stock Non-S-Line A4: 16mm
- Stock S-Line A4: 18mm
- Stock S4: 20mm
- Stock RS4: 22mm
- 034Motorsport Prototype: 25.4mm
Stiffness:
- Stock RS4: 380 lbs/inch
- 034Motorsport Prototype (Soft): 760 lbs/inch
- 034Motorsport Prototype (Firm): 850 lbs/inch
More details coming soon!