In what some might see as a rare and refreshing bow to public pressure, the California Air Resources Board this spring backed away from a proposal to force vehicle manufacturers and painters to use only new, high-tech reflective paints for coating cars and trucks sold in the Golden State. Even the Big Kahuna of conservative talk, Rush Limbaugh, had weighed in on the issue, labeling the CARB regulators "tyrants."

Tyrants they may or may not be, but even in its current, scaled-back version involving only vehicle windows, the so-called "cool cars" initiative being considered by Director Mary D. Nichols and others at CARB presents serious problems. These problems go far beyond the technological problems of developing a coating that can be readily applied to automobile glass and which will adhere for an extended period of time.

The cost of developing and applying the special coating is a worry to vehicle manufacturers, aftermarket windshield manufacturers, retailers, and consumers. Even though CARB recently exempted vehicles with plastic rear and side windows, such as Jeep's Wrangler, from the proposed mandatory coatings, serious concerns remain. And these misgivings extend well beyond our shores and the Big Three auto companies. Toyota, Nissan and other large foreign automakers recently urged California to back away from the window glazing proposal altogether.

The most serious concern – a truly major one – has to do with the fact that the metallic coating CARB is seeking to mandate interferes with electronic and radio signals emanating from or entering vehicles. Understandably, manufacturers, installers and users of the myriad of electronic devices now commonplace in private and commercial vehicles are deeply worried about the direction in which CARB is leading California.

CARB ignores such concerns at its own peril.

The basis on which this regulatory agency is proposing to mandate the "cool" coatings may be laudable – reducing interior temperatures of vehicles so drivers would run their air conditioners less, which would reduce the fuel consumed, which would lower carbon emissions, which would lead to a reduction in greenhouse gasses. Serious questions about the validity of the "science" underlying such a linear argument already have been raised. Even leaving those concerns aside, the signal-interference problems resulting from the reflective coating could lead to serious questions of liability.

For example, if a motorist whose vehicle is equipped with an emergency radio locator device, such as GM's OnStar system, and whose windows have been coated with the CARB-mandated "cool" coating is in an accident, and their system will not transmit an emergency signal or sends one with erroneous locator data because of interference caused by the window glazing, who will be liable? If a car or truck owner spends money to enjoy satellite radio, but then is unable to properly receive the program signals, what are they to do? Are they expected simply to "suck it up" because this is the "price they pay" for arguably lessened greenhouse gasses?

And what about state and federal law enforcement? Will officers accept the fact that tracking devices installed on vehicles (either by law enforcement themselves, or using the commercially installed devices that also can be tracked by law enforcement) may be impeded or useless because of interference from the "cool" glazing? Will agents from California's Bureau of Investigation & Intelligence accept that their investigations are being impeded by another state agency to arguably save a small amount of greenhouse gas from entering the atmosphere?

CARB is scheduled to issue its final regulations at the end of this month on whether to require the metallic glazing on all vehicles sold in California. Let's hope the glimmer of common sense that caused the agency earlier this year to back away from requiring reflective body paint on all such vehicles is once again employed to avoid an unnecessarily costly and destructive mandate that would hit auto manufacturers, electronic device manufacturers, and consumers at just the wrong time.

Bob Barr, a former Republican member of Congress from Georgia, practices law, teaches and writes frequently about government over-regulation.