There are many online based ETK systems like realoem and bmwfans.info for BMW parts and most work great, however none are as accurate and up to date as the ETK directly from BMW.
Luckily BMW has their ETK available online with a general login. To access it just press the link below and enter the following login information:
User name: eu111111
After logging in you will notice this screen where you can navigate the parts catalogue by the last 7 digits of your vin, by description or by graphics.