Well. I've apparently broken my 2.5 year streak of not modding the S4 (beyond interior LED's or wheels). I purchased and installed a CR-15 brace from a guy (u2nelson) who is making them on Audizine. Basically, its a front strut tower brace. The goal is to give a little more precise steering and remove some of the hesitation from sudden steering inputs. The S4 is a heavy beast and in their quest to give it a comfortable, luxurious ride, they've made it so its a little sketchy to make quick adjustments at higher speeds.
Audi has the studs available for it built into the strut towers underneath the front plastic cowl but instead of a proper brace, they included a stamped steel L-Shaped piece which is quite weak. This piece that I've bought goes right over top of the L-shaped piece and strengthens it. The belief on the Audi forums is that Audi avoided strengthening this area to avoid extra NVH and harshness over bumps.
On to the install:
For just a guy making these in his spare time, the packaging was professional and the communication was excellent. There was a delay in getting them anodized and James was very good at providing his customers with updates regarding expected shipping. When the package arrived via Canada Post, I found it was protected better than most actual companies protect their goods.
At this point, my wife told me to go outside because she didn't want me making a mess in the kitchen.
Unpacked, its just a square bar with various holes and slots cut into it for attaching and fitment around brackets. Instructions are included (but the pictures are hard to make out) and new hardware with locking nuts and zip ties.
First thing to do is to remove the plastic cowling beneath the windshield wipers. Two plastic screws (they dont break immediately like Subaru's!) and it comes off easy. Ignore the fact that the car seems to be covered in dead leaves. I was just in BC and left the car parked in a forest during a windstorm.
There is a wiring harness attached to the L-shaped bracket. Pull it off and zip tie it out of the way. I left the ziptieing until last so that I could figure out the best way to keep it out of the way.
I pulled the weather stripping out of the way to access the convenient cutouts to undo the stock nuts that are on the studs (they don't attach anything. they're just there!)
One of them does hold onto the washer reservoir. Undo it and pull it out of the way gently.
Slide the bar through the gap and wiggle it around from both sides until it drops down onto the studs.
Put the washer reservoir back on over the bar.
Install the provided washers and the locking nuts. Torque to 20 ft lbs.
Put everything back together and shine up the engine bay a little.
I found that the two inside studs were hard to tighten down using the socket. I think they're slightly off alignment from the outside two, so the socket rubs against the bar and eventually works itself off. I had to "convince" the socket to stay on the nut with a rubber mallet a couple of times. No big deal, but the holes could be larger.
Taking it for a quick spin, the steering does feel tighter on sudden corrections or changes of direction. The best way I can describe it is that the feeling of the suspension loading up before the car actually responds to the input is lessened. There used to be this delay as the weight transferred to the outside corner and while this doesn't get rid of it, it improves the feeling and confidence in the corners. I wasn't able to detect any increased NVH, even with the radio and A/C off and straining to hear it. I think I noticed that it follows ruts in the road a little more and is a bit more "lively" over large bumps in the road, but it could be that I am being super-sensitive to that.
For the price ($130USD), this is definitely a worthwhile mod for the Audi.
Next up: 034 Transmission and Rear Diff Mount Inserts.