Yeah man, our E90's aren't meant to be light cars. Your suggestions to reduce weight are good, but to effort+cost vs. benefit might not be enough. You can drop 150lb on a 3800lb, but what is that really going to do for you? More than likely, you aren't going to notice much of a difference, especially when you are racing 3000lb cars.
Another weight trimming suggestion...
You can go on a diet
