Alternator/generator/regulator problems of the 2006 BMW 3 Series

First the driver side door lock actuator would not unlock so I would have to use the key to unlock the driver door. Bought a new actuator and had it replaced. Not even one month later the back seat driver side door lock actuator went out as well. However there is no key hole for the back door and it cannot be opened from the inside. I was told by a BMW dealer that I would have to have the door torn off and replaced with a new door because there was no way to open the door. But wait there's more! both back window regulators went out as well! got the back seat passenger side fixed. But can't get the driver side done yet. This all happened within a year.