WHEN Gerald Dicker goes to bed, he likes to know his car is bunked down for the night too.
''If I'm sleeping and my car is not, I have a problem,'' says Mr. Dicker, a resident of Skokie, Ill.
To rest easier, Dicker signed up last week for a new, state-wide drive against auto theft. Under the program, a special rear-window sticker will alert police to pull over his car whenever they spot it on the road between 1 a.m. and 5 a.m.
Tens of thousands of US motorists like Dicker are inviting police to stop their cars during the wee hours when thieves -- not owners -- are likely to be behind the wheel. The sticker programs appeal to the elderly and others who rarely drive in the middle of the night, as well as to some parents of teens who may be tempted to break a curfew, organizers say.
Growing numbers of cities and states are promoting the aggressive strategy to combat car theft, the nation's fourth most common property crime. In 1993, the value of cars stolen in the United States reached nearly $7.5 billion. Illinois ranked fifth nationally for its rate of auto theft, state officials say.
Illinois seeks to register 20,000 car owners in its new Beat Auto Theft (BAT) program over the next year or 18 months, says Jim Naydar of the Illinois Motor Vehicle Theft Prevention Council.
Similar programs have already worked well in US cities including Houston, Washington, and New York, which pioneered the anti-theft strategy in 1986. Of the 78,000 vehicles enrolled in New York City's ''Combat Auto Theft'' plan, 181 have been stolen and 26 of those were recovered. In Houston, six of 9,000 registered cars were stolen and all were recovered. Tulsa, Okla., reported a 50 percent reduction in its auto theft rate as a result of the sticker program.
The Illinois BAT program is unique, however, because it is a centralized, state-wide effort.
''We think our program will be more successful because of our central [auto] registration system and instantaneous access to the computer data base,'' says Jack Pecoraro, director of the Illinois secretary of state's department of police.
When an Illinois motorist enrolls a car in the BAT program, that information is recorded under the license plate number in a central computer system, where it is available within seconds to every patrolman in the state.
''If you register your car in [Chicago's] Cook County, and your car is downstate in Carbondale, Ill. at two in the morning, it will be stopped,'' Mr. Pecoraro says.
Police who spot a car bearing the 2 1/2-inch by 5-inch BAT rear windshield sticker during the designated hours automatically have ''probable cause'' to pull the vehicle over and check the driver's auto registration documents and license.
Thieves cannot easily remove the stickers, police say. ''They would have to use a razor blade. It would really slow them down,'' says Jim Chwalisz, crime prevention officer at the Skokie police department.
Some civil libertarians worry that motorists may be pressured into authorizing the early morning police surveillance by insurance companies.
In Illinois, the insurance industry paid for the BAT program's $170,000 start-up cost from a trust fund that pools one dollar for each car insured. (Motorists also pay a $5-per-car fee to enroll in the BAT.)
But others, including the American Civil Liberties Union, disagree. They stress that car owners volunteer to take part in the program and can easily withdraw by mailing in a cancellation form.
Many motorists apparently feel that the benefits of the BAT and similar programs are outweigh the inconveniences.
''If I had to be out at 2 a.m. and a police officer stopped me, I would think he was doing an excellent job,'' Dicker says. ''I think this is an absolute plus.''