Still have my SCA 21mm bar.....
no broken subframe mounts but I did bend brackets like no other. My fix, I bought the large U brackets and grooved poly bushings that Aussie recommended for his bar in the 21mm size.
I rigged it up using the stock bolt and mount and also went to the hardware store and bought some high grade bolts, lock nuts, and a few fat washers. I ran the bolt down the hole where the stock bracket notched into with a washer on each side. I ran the nut up and tightedned it down. Its been a year or more and no problems.
I've never autocrossed but I'm sure if I was still running the stock brackets I would have tore the subframe mounts off. Once the stock brackets bend themself out of shape it then is a constant banging sound where the bracket is hammering itself against the stock mount.
