Twin chassis

Two chassis. An outer aerodynamic chassis carried downforce directly to the wheels through its own springing; an inner chassis carried the cockpit and suspension. The outer structure could be driven hard onto the ground by aero load while the driver rode on a compliant inner tub — recovering skirt-like sealing without skirts.

Skirts were banned; nothing explicitly forbade a second sprung structure. Colin Chapman's argument was that the aero chassis was the sprung part for its own purposes.

Never measured on track.

Rivals protested that the twin tub constituted a movable aerodynamic device. The protests were upheld and the car banned. Chapman abandoned the design and updated two Lotus 87 chassis instead.

The 88 never raced.

The reasoning — that all aerodynamic bodywork must be rigidly secured and immobile relative to the sprung part of the car — is the clause that later killed the mass damper and FRIC.