For example, how do rain-sensing windshield wipers work?
–F.S., Chicago A. Rain-sensing wipers generally use infrared sensors to monitor a section of the windshield for moisture or dirt — and then activate the wipers to respond, according to a threshold a driver sets. Q. My 1990 Subaru has gone 70,000 miles. I changed its engine oil every three months when I drove 4,000 miles annually. Now I change oil only once a year because I just drive 700 miles annually. That OK? –W.M. Bolingbrook A. I suspect you do lots of stop-and-go driving at that low mileage — or let the car sit for long periods. In either case, change the oil every six months. Q. I gave up trying to work my BMW’s “iDrive” system, which I must use with its console control rotary knob and dashboard screen for anything except simple audio and climate adjustments. Everything else involves using iDrive with its distracting menus, submenus and settings. That’s dangerous when the car is moving, so what’s the point of it? –E.H., Highland Park A. BMW says iDrive eliminates a confusin
