I agree with you about the weight. Adding weight doesn't seen to be a good idea to me either. Stock brakes, even with cooling, are way overloaded in racing. And tires cost money. And overloaded broken parts cause wasted weekends.
BooHooHoo.
Really. Nobody was all that concerned about this when they slapped a 2690lb minimum weight on an Integra GSR. Thats 2700lbs on a car equipped with the exact same brakes that come on the Honda Civic EX and Del Sol that are classed at under 2400lbs. Oh, and thats 2700lbs on a FWD car, you know, a car with the front tires doing everydamnedthing... Yeah, right. As I said... BooFrigginHoo for the BMW boys.
So BMW guys need not start bitching about brake parts and tires due to added weight. All you'd be getting is what other guys already have.
Scott, who laughed when he read that stuff.