Car and Driver asked us to test windshields for an article appearing in its August, 1998, issue. There are two kinds of cars, the magazine reports; "okay" and "terrible."

We found that all windshields reduce radar detector range by a minor amount. These are the "okay" cars. V1 can easily live with those losses.

The "terrible" cars cut radar detector range by 95 percent. Even V1 can't protect you through those windshields.

The "terrible" windshields all have a silver-based metallic film between laminations, usually put there to reflect the sun's infrared radiation. Ford had a different idea with its InstaClear system (now out of production), which used the film as a defroster.

Here's a list of "terrible" cars:

•	Audi A8 with optional "insulated glass" (look for a bronze tint).
•	Some Ford Taurus, Mercury Sable, Lincoln Town Car, and Lincoln Continental models with optional InstaClear (look for a bronze tint).
•	General Motors--All 1989-1996 Chevrolet Lumina minivan, Pontiac Trans Sport, Oldsmobile Silhouette; all 1998 and newer Chevrolet Venture, Pontiac Trans Sport, Olds Silhouette minivans; some 90s Buick Roadmasters and Chevrolet Impala SSs; some late-80s/early-90s Corvettes (look for a red-bronze tint).

SOME STICK-ON WINDOW TINT FILMS ARE "TERRIBLE" TOO. Some tint films also have metallized layers. Car and Driver supplied samples from Wal-Mart (Axius brand) and AutoZone (Gila brand). The Axius films have no effect on radar reception in our tests.

However, the Gila package claims its films have metallized layers, and our tests of Gila films produced the significant radar loses we associate with metallized films.