Well, let's see what Reeves Callaway did to stiffen up that beam.
Simple, he welded a big ass bar to the beam.
There are some other ways to stiffen the rear beam without poking holes in it. I replaced the rubber bushings with delerin. This forces the beam to twist about the bushing axes, rather than the middle of the beam section. I also added an autotech/neuspeed style rear bar, and run a GLI front bar (the biggest stock A2 option). Now I am not autocrossing, so I may not have the same perspective as you folks, but I have not found that a rear bar induces "snap" oversteer (though drivers certainly can make that mistake more dramatically with one).
There are some alternate schools of thought that getting good rotation can be done by softening the rear beam bushings - see Mike Ogren's fwd VW racing guide for more info.
Last edited by suki101; 04-30-2012 at 06:48 PM.