Sharraxaadda

The woman who apparently took over this house from its deceased owner, her uncle, left a car--BMW with Maine license plate 7398 XV-- and has not been back in a long time. Vegetation is severely overgrown. Mail is falling out of the mailbox. I live nearby. What can be done? Is it legal for me to clean up the yard? Can the woman be identified (from the license plate) & contacted? Thanks.