mine, on my r/h drive, uk reg 307 is in the drivers side, but either way its fairly easy to locate, its the little bump underneath the mirror support, close to the door. Run your hand below the mirror and you will feel it, whatever mirror its on.Passenger mirror in the UK.
mine IS manual adjustment, maybe thats why its on the drivers side? Or maybe they just changed it as they saw fit? Either side, it does not matter much, its the same sensor, working the same way. I have just ordered a new one on ebay for less than a tenner, lets see it it works now. I will keep you posted!But when i was shopping for a new mirror i found that all the cheap ones were with no sensor and no electric adjustment. Those more basic models with manual adjustment must have the sensor somewhere else.