We bought a Toyota in Thailand in 2004 that instantly flattened its battery. The culprit was the interior light 'see you out' dimmer switch that turned the light off after we got out of the car but remained 'open circuit' and drained the battery overnight. Switching off the interior light entirely solved the problem. I hired a later model of the same Toyota in Thailand this year and it, too, had the interior light permanently switched off. So this is a common fault with Toyotas.