The Mystery of the "Bird House Holes": A 1970s Avanti Cooling Experiment
Have you noticed a series of unusual holes drilled into the inner fenders of your 1970s Avanti? Often called "Bird House Holes," these were a unique factory attempt by Avanti Motors to lower under-hood temperatures. In this article, Dan Booth explores the history of this design—from the early "progressive" hole sizes to the standardized four-hole pattern used after 1973.
Discover why this cooling experiment was ultimately abandoned, not because it failed to vent heat, but because it created a surprising winter-weather hazard: frozen hood locks. Learn how the factory authorized specialized dealers like Nostalgic Motor Cars to "glass up" these holes to prevent ice from trapping owners out of their engine bays. It’s a fascinating look at the hands-on engineering that defines the Avanti legacy.