All You Had to Say (2005)

After a hit and run, two twenty somethings discover the bum they hit is still alive. Luckily, they've seen I Know What You Did Last Summer, so they realize exactly what's going to happen. The bum's going to stalk them and begin to kill them and their friends off on by one, while leaving cryptic notes. So they decide to take a preemptive strike. Get to know the bum, befriend him and if necessary turn the tables. Never mind the fact that he's a friendly guy who has shown no signs of recognition. He's a serial killer who knows everything and wants to gut them and drink their blood. And the only way to prevent this is for them to stay one step ahead. After all, keep your friends close and the bums you smash with your car even closer.