The Mendham Borough Police Department is notifying the public that there has been a large increase in high-end motor vehicle thefts throughout Northern New Jersey.  They are urging everyone to keep their vehicles locked at all times and to report any suspicious activity to the Police Department immediately by calling 973-543-2527.  They are also recommending to remove all valuables from the vehicles at night, including keys, wallets, purses, cash, electronics, etc.