I have been collecting all the braces, mounts inserts and stiffeners offered over the last two years. A few are in and a bunch to go. I learned my lessons on a B5 S4 with installing too many at once: “What is that whine?!?” On the RS5 I slowwwwwly introduce a new one and drive it for a while. Then try another. If it adds anything negative I am Comfortable removing it and trying the next option. Here’s how it sits currently:

Installed:
Trans Brace (Like it)
CR-15 (Like it)
Rear Diff carrier inserts (Like it)

Not yet Installed:
Alukruz
O34 Sway
034 solid end links
034 Sub frame inserts
Apikol Rear Diff Mount
034 Trans mount

Nothing bad so far. I’m leary about the solid sway bar end links being noisy though.