There are two braces under the dash that help keep the windshield posts in place. My guess is they are missing on this car and this was their solution to the problem of keeping the glass from breaking.
Neither of my Darrins, an early car and a later car, have anything like the braces pictured.
DTort is correct, there's not a lot of real estate in the foot well and with these things in the way, there's even less.
