At VIR this past weekend, a driver filed a protest against two cars, citing missing stock parts. Both protested cars were missing the panels behind the headlights and one was missing the left side exterior headlight surround grill trim. The protester was concerned that the missing parts allowed more, and cooler air into the intake, giving a performance advantage. Without the panel and the exterior grill on one car, the intake did have a very good "view" of the outside.
After a lengthy discussion, that unfortunately got a bit emotional but not extremely heated, the protester chose to withdraw the protest, if the drivers of the protested cars agreed to install the missing parts by the next race weekend.
Admirably, the two drivers found the missing parts and installed them prior to the Sunday race.
During the discussion (I was called as a Spec E30 official) the protested drivers explained that the panels were missing when they bought the cars. However, the driver is responsible for the car, regardless of who built it or how it was raced in the past. If an item is protested, all the NASA Compliance officials care about is right here and right now.
If you have any questions about your car, look at the Rules very carefully. You might also examine a well-kept E30 street car.