Audi TT RS Lower Control Arm rear bushing
Part number: 8S0-407-183-B

The Audi TT LCA rear bushing is solid, rather than skeletonized (webbed) the way the Golf/Jetta/GTI one is. It's less flexible than the OEM bushing, so it improves steering precision and input.

Audi parts 5Q0-407-183-L & 81A-407-183 cross reference, but might not be as stiff (but still stiffer than Golf OEM)

8S0-407-183-B
rubber profile
O.D. 65 mm
I.D. 13 mm
outside thickness 30 mm
inside thickness 50 mm