Rear sway reinforcement brackets necessary?
 

I picked up a used TRD rear sway locally, but it came without the mount reinforcement plates. They seem to be oddly pricey from Toyota, and I'd have to run the stock ones to stay in street class autocross.

Are they necessary on a street/autocross driven 2017? I'll be running street tires on stock wheels, no R compounds or anything. The 2017 has a stiffer rear sway to begin with, so I imagine if there was an issue with attachment point strength it would've been rectified.

I'm answering my own question in case anyone is wondering in the future.

Yes, you do need the reinforcement plates. The supplied bushings don't fit right without them.

Personally I would if I had a bigger rear bar. Have you seen how the bushing brackets mount to the rear subframe? It looks like there's only 2 pinch welds on both sides of the mounting point. Once that snaps off it'll never go on the same way again.

Where did you find a part number for these? There isn't one listed from Toyota, and TRD has been unresponsive.