My Alfa, a 72 GTV coupe, like all GTVs of its approximate vintage, has a recessed panel in the headliner over the back seats. It has proven to be a mystery to passengers in the car, looking like the cruelest joke of a sun roof for the rear passengers who are otherwise treated poorly by the car's design. So cruel, in fact, that a sticker was placed on the rear windows by Alfa. When viewed from the outside, it read:
GROUP 2 TOURING CHAMPION 1971
EUROPEAN MANUFACTURES SERIES
This side of the sticker explains in part the pseudo-sun roof. The GTV raced in the sedan class. To comply with sedan class regulation, there had to be a specific number of inches of headroom for the two passengers in the back seat. Hence the "cheat" of recessing a spot in the headliner, because the seats were as low as they could go. So you can race, and sometimes beat, Minis, BMW 2002s and Datsun 510s.
From the inside, the other story of compliance was visible. From a knees-to-chin head-ducked position, the contorted rear seat passenger could read the obverse:
TO BE OCCUPIED BY PASSENGERS
WHILE VEHICLE IS IN MOTION
The other set of regulations the GTV had to comply with were written by the US Department of Transportation, that defined of sports cars and sedans. Being classified by the DOT as a two-seater would require less modification of Alfa's aging (yet still stylish) design - less in the way of bumper protection for the would be passengers. Actually taking the seats out and putting in a package shelf (a la 911) would make it race in an uncompetitive class. Hence the sticker forbidding rear seat passenger, which attempts to serve both masters. (I'm guessing the seat belts back there are for securing cases of Chianti and bundles of pastrami.)
The different approaches in compliance reflect the different levels of enforcement. Perhaps Alfa felt it could convince the DOT that, really, who would ever be so silly as to sit back there? This is a sporting coupe, not a sedan. However, Alfa knew that the sanctioning bodies for the racing series they participated in would be out there with tape measures and calipers before every single race for tech inspection. Alfa's compliance would be challenged by every other team on the track.
I don't believe it would be too far off the mark to say that an implementation of a control, especially a compliance control that may not have a palpable financial return, will be as effective as the perceived enforcement.
(Read the story of the 2.5 liter Trans-Am at 1971 Laguna Seca for more sad stories of compliance. The Datsun version, the Alfa version. "Oversize fuel lines" vs "expanding gas tanks." )
(sticker image courtesy Papajam at the AlfaBB)