Send a certified return receipt letter advising him of storage charges, Make sure you have a sign posted in the reception area noting storage will be charged if left after 3 days, I am in Vt and was just given title to two cars thru the states abandoned vehicle dept. Ma probably has a similar law, I had a customer that had me tow in his 09 Impreza that had been sitting for over a year, a few weeks later I told him his car was finished, He came in & paid the bill and told me he would be back to pick up the car. NEVER TO BE HEARD FROM AGAIN! After 3 months I declared it abandoned and am now the proud owner. Pain in the tail but worth it.

Scott Freebern
Owner/Technician
Manchester Engine Works
Manchester, Vermont, USA