It's a problem that has baffled German engineers, auto industry experts, Kern County road engineers and, most importantly, Samuel Wattles of Rosamond: How do you make a left turn in a new Smart Car? Wattles waited a year and a half for his Smart ForTwo - a tiny, two-passenger car that gets more than 40 miles per gallon - only to find that the lightweight vehicle wasn't heavy enough to set off the sensors that activate left-turn signal lights at intersections. At least, that's what he thought was going on when he picked up the car July 20 in North...