For good reason, Pennsylvania law insists you clear the ice and snow off your entire vehicle. So don’t be the one caught with 10-inch viewing circles carved out of the snow on the windshield and driver-side window. Oh, and that two-foot car-top drift you’re waiting to blow away harmlessly while you drive down the highway? Forget about using that shortcut. Chances are, the pile will stay put, melt during the day, freeze solid by five p.m., and slide forward onto your windshield at the first red light on your homeward commute. Or shatter the windshield of the vehicle behind you when you pull away from the intersection.