Good point. The neuspeed 21mm would make the car quite the handful during agressive driving, or wet/snowy weather.

 

If I'm not mistaken an untouched factory audi would probably get loose if you had that much sway bar in it. I would go with the smaller adjustable one and just get the understeer out of the car.

 

I've heard of people tearing the subframe with a HUGE rear bar. Then again it was on a civic with no front bar.

I know I would be a little bit warry of doing more than 110 mph with a 21 mm rear bar, I'd have to get really used to it first.