Ever wonder why you can't buy a car in Illinois on Sunday? So auto dealers can take the day off without fear that you'll find someone else to sell you one, that's why. Back in 1982, they got the General Assembly to pass a law requiring their competitors to take the day off, too.

The argument was that staying open seven days a week was too costly for the struggling auto industry. Closing on Sunday would save on payroll and overhead and (they really said this) promote attendance at church.

"We can hire a better-caliber salesman, a family-oriented man whose family wants him home on Sunday," the president of the Chicago Automobile Trade Association said at the time. "The public will benefit as a result."

The public did not benefit, of course. Weekends are prime shopping time, but the law cuts the car-buying window in half. How many showrooms can you visit on a given Saturday? For consumers, this law means fewer choices and less competition. Car shoppers would be delighted to see it hit the junk heap.

So we're all for state Sen. Jim Oberweis' attempt to repeal the law, though we expect he'll find traffic running one way against it in Springfield. That's because car buyers don't have lobbyists to represent them.

It took several tries over several decades to enact the no-Sunday-sales law. In 1951 and again in 1957, the legislature passed bills to prohibit selling cars on Sunday. Gov. Adlai Stevenson vetoed the first one, and Gov. William Stratton vetoed the second. Gov. Otto Kerner signed the third bill, in 1961, but the Illinois Supreme Court struck it down.

When the current law passed in 1982, a handful of dealers who wanted to sell cars on Sundays challenged it all the way to the U.S. Supreme Court. They lost. The Tribune's editorial, headlined Illinois, you're stuck with it, began like this: "In refusing to scrap an Illinois law barring auto sales on Sunday, the U.S. Supreme Court simply said that a state can pass any nitwit law it likes, as long as it doesn't conflict with federal standards."

Of course, the General Assembly has no business passing nitwit laws to shield any business from competition. Imagine what would happen if grocers were spared from staffing their stores on Sunday, or if the 9-to-9 drugstores could get the legislature to outlaw their 24-hour competitors. What if restaurants were required to close on Monday, a notoriously slow night for dining out?

All of those businesses are free to hang up a "closed" sign at any time, of course. The difference is that consumers are free to spend their money elsewhere. Thanks to the General Assembly, auto dealers don't have to worry about that. How convenient for them! And inconvenient for the rest of us.