Um, how tall are you? I'm 6'7" and have NEVER had a need for any more leg room in any of my BMWs. Porsche's? Yes. As a matter of fact, I bought an E34 after knee surgery as it was the only car I could find that would let me have my legs completely straight.
Sorry to threadjack, but this has to be the first time I've ever heard of this being necessary. I dunno, maybe I just like to be at the controls a bit more...