E.V.P.'s

I've had a few experiences with EVP. Some friends of mine found a crypt with its door slightly ajar; they were able to put a tape recorder inside. When they checked the tape there was what sounded like a deep male voice saying "just go." Also there was one instance when myself and several friends were standing around a cross near a cemetery late at night. We had a tape recorder running, and later when we played it back there was a distinct whistling sound; the brief sharp kind of a whistle you use to get someone's attention. None of us remember hearing whistling at the time of it being recorded, but of course that might just mean we were unobservant. By far the strangest EVP like thing I've come across was when I was driving and had a digital recorder running for a lark. Out of nowhere I heard a loud explosion and the sound of metal scraping underneath my car. Of course I stopped and got out immediately, but I couldn't find anything wrong, or anything on the ground nearby, or anything dragging under my car. I thought that it was pretty strange, and just got back in the car. I turned the recorder off and ran it back a minute or so, and sure enough it had caught the sound of the "explosion" and subsequent scraping sounds. I never heard any sounds like it again, and it turned out there wasn't anything wrong with my car. And one other thing about this that seemed really odd to me; sometimes the "explosion" on the recording seems to move. When I run the recording from the beginning, the "explosion" will be heard anywhere from 7m41s to 7m53s. Maybe it's just the fault of a cheap $50 digital recorder. But it doesn't seem to have timing inconsistencies with any other sounds, just this one. Sort of a weird story, huh?