The American Automobile Association says it rescued more than four-million drivers who locked themselves out of a vehicle in 2012.It's all to do with the phenomenon of "keyless entry", where you press a button on a key fob and, hey presto!, the doors open.They're fine unless they get wet - think dropping one in a puddled car-park - and the basic ones are cheaply replaceable. Lose or damage a fully electronic key with “smart” functions and the replacement cost could cause a hernia (we're talking thousands, here).LOCKED OUTSouth African AA members are as prone to key trouble as their US counterparts: nearly one in 20 needed help in 2012, with about 80% locked out of their vehicle. So, while modern technology makes entering and starting a vehicle more convenient, it can be defeated by that most human of emotions: forgetfulness. To ensure the key to your car works reliably, take care to protect it from the elements, avoid exposing it to hard shocks or extreme temperatures, become familiar with all its features.Oh yes, and replace its battery at the recommended intervals...Have you had similar issues with keyless entry? Email us and we'll publish your thoughts on Wheels24.