Whats better for autocrossing?

BMR Xtreme Torque Arm kit with BMR boxed subframes or G2 subframe V-Braces and Drive Shaft Loop with G2 torque arm?

Neither. Subframe connectors bump you up to an unreasonable class if you do SCCA autocross.

You'd be much better off with first buying R-compound tires and an extra set of wheels. After that, shocks, sway bars and springs. Then after that a T2R differential. Then after that, some better brake pads.

Whatever you decide, I would get the suspension pieces from LG Motorsports over the BMRs. The owner has been doing autocrossing for many years and his stuff is proven to work very well for it.

You'd be much better off with first buying R-compound tires and an extra set of wheels.

True story, get a good set of tires. Tires are 2/3s of your handling, best mod you can do for your car.

:)