I have been using the Zed a fair bit recently to do long distances with work. On Monday I arrived after a 7 hour drive to the South coast and for about the last 30 miles I could hear a strange whirring noise from behind the drivers seat, when I stopped the engine I could still hear it and could feel a slight vibration. it sounded like a motor running on even though the keys were removed from the ignition. Fearing the worst and thinking I would return to the car in the morning and find a flat battery I went on the troubleshooting hunt and eventually found it was coming from the boot......... infact, from my bag..... it was my rechargeable toothbrush. relief and self ridicule at the same time. 
