Anyone that has sold a vehicle...........

Here's my situation: I've been trying to sell my truck, well on Friday someone came to look @ it and they decided they wanted to drive it also. They had it for quite some time. Now today I walk out my house and notice a spot on my driveway. I pop the hood, there's coolant leaking from my top radiator hose and I also notice that my battery was shifted and find that the bolt for the bracket holding it in place is quite loose. Anybody have any idea of what they possibly could have been up to under the hood or experience stuff like this????