By DEANNA BOYD FORT WORTH — A 15-year-old boy found dead Wednesday morning after taking his mother’s car for a joy ride had also stolen and wrecked another car last week, police said.Police suspect Donovan Yadwisiak, a Fossil Ridge High School freshman, may have been erratically driving the Toyota Prius — a car that his mother had rented after the first crash — when he struck a curb and plowed into a light pole behind a shopping center at the intersection of Beach Street and North Tarrant Parkway.A Fort Worth police officer discovered the wrecked car about 7:50 a.m.