Disgorged Matter?

On our way out of town, within seconds of driving away from Echo (ECHO?), we noticed an odor quite similar to the one that hovered in the kitchen that one day. At first we believed that, oh no, it had been one of us all along--my God, we brought a vomitty smell with us! Then, after the odor dissipated (as if it had been lingering in the air around the car, had been sucked into the circulation system, and then had blown away once we left the area), we concluded that Gock must have been correct: icky, scary bile gas of some unusual sort floats around Fletcher Place!