The family of Brian Laundrie — who vanished as authorities hunted for his girlfriend Gabby Petito — found a note left on his car in Florida, their attorney told The Post Monday. Police left behind the notice on Laundrie’s Mustang, which his family found Wednesday parked near the Carlton Reserve in Sarasota County, according to attorney Steven Bertolino. The note had asked for the car to be removed — but the family left the vehicle there until Thursday, hoping he’d return to it, Bertolino said. Laundrie, 23, took off on a supposed hike of the 25,000-acre nature preserve on Tuesday...