1999-2002 Panoz LMP-1 Roadster S

Images courtesy and copyright Andrew Wong and Michael J. Fuller
Text copyright Michael J. Fuller

The rear diffuser is full width with multiple strakes.  ACO rules state that the diffuser must remain within the contour of the bodywork.  Yet on the Panoz it clearly extends beyond the trailing edge of the rear bodywork.  But note the additional structure sandwiched above the diffuser.  That is interpreted as the actual rearward extent of the rear bodywork and therefore the diffuser is in legal compliance.
The notched endplate encourages air to flow in towards the slot gap adding energy to the flow, increasing downforce in yaw conditions.  There would be little, if any performance gain in a straight line and this device would have to be optimized in a yawing road wind tunnel.
The strake in this picture helps evacuate the wheel well high pressure air.
A triple set of dive planes helps balance the chassis at higher downforce circuits.

©Copyright 2002, Michael J. Fuller