Thousands New South Wales motorists have been overcharged for their green slips after NRMA Insurance applied incorrect risk ratings to the locations in which vehicles were garaged. newsiviewlistenLoading ABC NewsNews HomeNRMA Insurance fined $500,000 by regulator for overcharging NSW drivers for green slipsShareShare articleNRMA Insurance fined $500,000 by regulator for overcharging NSW drivers for green slipsBy state political reporter Nick DoleTopic:Insurance.