SAUGUS-Dive teams turned up nothing after an extensive search of the Saugus River late Friday night for a possible sunken car, firefighters said Sunday.At approximately 9 p.m. Friday, a woman called police saying a car drove down a boat ramp and into the river with its headlights on. The car floated for a short time before descending from her view, she told police.”They didn’t find anything,” Fire Capt. Chris Rizza said Sunday. “With the water coming in and out, they have an idea of where the car [possibly] moved to.”Saugus firefighters quickly took a boat onto the cold river after the initial call Friday. They were later assisted by the Cambridge Fire Dept. Dive Team and the Lynn Fire Department for over four hours.Town officials say numerous stolen vehicles were previously dumped in the Saugus River.