Here are some things that have been done to me. If you have access to his car keys, move it somewhere else in the lot. A sandwich with styrofoam in it. Don't actually let him eat any though. Get in a trash can, if you have the big ones and jump out.
We did this to a friend at his house, if you know how to get in. Take some of his clothes and stuff them, put boots on the stuffed dummie's feet a baseball hat or something on some stuffing for a head, and set it in a chair ( we also put a beer bottle in it's hand. Scares the heck out of you when you walk in the door.