WASHINGTON—General Motors Co. on Wednesday recommended that Chevrolet Bolt electric vehicle owners parking in decks do so on the top floor or on an open level, at least 50 feet away from other vehicles, citing potential fire risks. The precaution would “reduce potential damage to structures and nearby vehicles in the rare event of a potential fire,” a company spokesman said in an email. GM sent a notice to consumers who had asked about parking issues, he added. GM had previously asked owners to park Bolt vehicles outdoors, away from structures, and to not charge them overnight. GM also urged owners to not leave Bolt EVs charging unattended, even if using a charging station in a parking deck. Bloomberg News reported the recommendation earlier. GM in August widened its Bolt recall to more than 140,000 vehicles to replace battery modules, at a cost now estimated at $1.8 billion after reports …