Scaredy Cat Stephanie

So last night, Casey worked, as he is again tonight. When he got home at 6 AM, he asked me who was over last night, so I said Brooke and Colton. He said, no who was over in the driveway? Now I'm clueless as to what he's talking about, so he points out to me several large, fresh oil spots, one right behind my car and several at the end of the driveway. I have no idea where they came from, I never heard anything last night and my trusty guard dog, Onyx never stirred from her comfy bed on the floor. So, now I'm a little creeped out. I actually locked all the doors, we rarely lock the doors, so much so that Casey doesn't even have a key on his key ring... Now, everytime a car stops at the stop sign right across the road, I peak quietly out the window, just to make sure... This is going to be a long night...