That's the lesson of the windshield test Car and Driver asked us to do for its August, 1998, issue.

TO A LASER DETECTOR, laser looks like a faint light. Spotting a faint light in bright daylight is hard to do; as a result, laser detectors provide less protection on sunny days. But on overcast days, detectors do much better, and V1 works very well at night.

The windshield changes a laser detector's vision exactly as sunglasses change yours. The view is so bright on a sunny day that sunglasses don't hurt. But your detector doesn't want sunglasses any time you wouldn't wear them. That means that darker windshields hurt laser-detector performance on gray days and at night.

TEST CONCLUSIONS:

1. All windshields provide significant losses in laser detection.

2. The least-harmful windshields still cut laser-detector range by 60 percent; the worst ones cut up to 80 percent.

3. Avoid putting your detector behind the tint band at the top, unless you're sure it has no effect. We found major losses due to the tint on some cars, and no additional losses on others.

4. Road splash on your windshield hurts laser detection, but the splash sample we tested--it was so bad a driver would stop to wash the glass--hurt laser detection less than some tint bands.

5. Recent model years suggest a trend; that car makers are moving toward glass formulations which cause greater laser losses.

DO-IT-YOURSELF WINDOW TINTING FILMS: Car and Driver supplied four tint-film samples, which we tested on clear window glass. Clear glass cuts laser range by about 25 percent, and all of the samples cut laser range by an additional 25-35 percent. Metallized films had about the same effect as ordinary tint films.

You might add a tint strip across the top of your windshield to cut glare. If so, a laser detector will suffer a serious loss of performance when placed behind the tint.

REAR-LASER DETECTION would be hurt by tint films on rear and side windows, at least in theory. V1's rear-laser performance is by far the best in the industry, but don't expect too much from it. When you're shot in the back, you're moving away, so the shooter's best shot is his first one. If he fails to get a reading on his first shot, you're so lucky you don't need a laser detector.

HOW WINDSHIELDS CHOP LASER DETECTION RANGE...what's left after passing through the windshield, arranged from best to worst.

CAR	MAIN AREA	TINT BAND
1989 Toyota Camry	40%	40%
1995 Nissan Maxima	40%	16%
1998 Olds Silhouette	40%	14%
1987 Corvette	32%	32%
1998 BMW 740i	32%	32%
1998 Porsche 911 Turbo	28%	28%
1998 Porsche Boxster	28%	28%
1995 Dodge Neon	28%	28%
1998 Chevrolet Cavalier	28%	no tint
1998 Mercedes Benz SLK	27%	no tint
1998 Honda Accord	27%	27%
1998 Honda Prelude	25%	no tint
1998 Audi A8	25%	no tint
1998 Corvette	24%	19%
1998 Ford Taurus	20%	13%
1998 Chrysler Concorde	18%	8%
1998 Toyota Camry	15%	6%
HOW DO-IT-YOURSELF GLASS TINTING FILMS CUT LASER RANGE...what's left after passing through the sample.
Clear glass, no tint		75%
Axius, 35% VLT on clear glass		53%
Axius, 20% VLT on clear glass		40%
Gila HPB046, 40% Smoke on clear glass		45%
Gila HPB044, 20% Limo Black on clear glass		50%

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