Stepped out of the car tonight, pressed on lock on the keyfob and it didn't lock. This sometimes happens when I lock or unlock and I just keep pressing it until it finally gives. This time I stood for a good 30secs pressing lock but could hear this 'tick tock' everytime I pressed on it from the rear drivers side arch above the wheel. I would press on Lock and it would make that 'tick tock' sound. The car wouldn't lock by the way but kept making that sound everytime I pressed on lock on the keyfob then eventually it just locked. Now this can't be what I thought which was a dieing battery in the keyfob so what is it...?