Good Photo
If I were to hazard a guess at a rational explanation I would say that the object is a reflection in the window of the car of something within the car itself. We had a similar photo a few years back of what appeared to be a skeleton digging in a back yard. This turned out to be the reflection of a snooker trophy in the bedroom window, caused by the flash bouncing from the window. The UFO seems to be at a similar angle in both pics
Other than that I have no idea.