Another quirky thing recently - my wife and I each bought new Pontiac Pursuit cars. Hers is an '06 model and mine an '05. They're both identical except for the color and transmission (she got auto...I bought a manual).
Lately we've been hearing a bizarre knocking sound in both cars, coming from the rear of the vehicles. The knock is identical to someone rapping on a door 4 times, as if someone had approached the vehicle from behind and knocked lightly on the trunk lid.
We're quite convinced its not someone trapped in the trunk, either.
- we'd have smelled that after awhile I think.
No shit. I've heard it twice in my car, she's heard it a few times in her car...and we've both heard it together in her car.
At first I thought perhaps it was some sort of built-in warning sound or something that came through on the sound system. But I've heard it when the stereo was off. And its not a mechanical knock...at least none that I've ever heard in all my years of owning and driving vehicles. Its always four low knocks.
I'm sure there's an explanation somewhere. But it still has me baffled at this point.