It’s hard to tell exactly how much just these bushings did as I also put in the STI Group N transmission mount and a Torque Solution pitch stop mount at the same time. Took a lot of the slop out of the drivetrain.

Make sure to mark/note how the original bushings come off the transmission cradle. There are plenty of videos out there on how to do this. Other then remembering where the bushings go this is a great kit. It's difficult to state the significant of this single upgrade as I did this with the Group N Transmission and Pitch stop mounts. Great supporting mod before anyone starts increasing engine power.

I installed these on my 2015 STI. Install was easy each bushing is labeled and the instructions are good. I noticed the shifter was less rubbery and the shifts were crisper. I didn't notice any more noise or vibration from these even though they are much stiffer rubber than stock.