Check out
http://www.mods4cars.com/
They have a device you can wire up for the 3 series that does this. I have emailed them asking for support on the 1 series. I'm sure if people put in requests it may get done faster.
Product Features:- Remote window control: One-Touch operation of the windows and sunroof with the original remote on all models (US and Euro)
- Automatic door unlocking when ignition is turned off. Aviod having to pull the door handles twice to get out.
- Automatic folding mirrors by remote (Factory option motorized mirrors required)
- User programmable: The module can be individually enabled or disabled. All settings are retained even if the car battery is disconnected.
- Shop/Diagnose mode: If activated the module is completely passive, as if it was not installed at all. It becomes invisible to diagnostic tools.