An unsuccessful buggy design that went hard-core to tackle the weight reduction issue, was one in the '70's called 'Sinex' by Sigma Nu. It was a front loader with a foam/fiberglass composite chassis, and a nose cone. The axle were composite too. This thing was too lightly built for the materials, and basically did not hold up - but it was 1/2 the weight of the buddies of the area.
SAE's first buggy (after it's success with 2 wheelers), was an all- aluminum monocoque (including the body) front loader called 2024 (after the alloy of which it was made). It was built by a brother who worked from Grumman, and had a zillion ribs inside and a thin aluminum skin - somewhat like a real plane is built. It was very light and we had lousy wheels, and the mechanical systems (steering and 4-wheel suspension) were complex.
* "I love the smell of solvents at Free Roll. It smells like......victory".
* "I'm loosing my mind, but I don't seem to miss it much."