I was going to answer your question, but it looks like someone already did. Are you "hyde" in Bimmerfest?
Well, here's the part numbers:
Left fog light lens: 63177224643
Right fog light lens: 63177224644
Full fog light information on each engine model for your E70:
http://www.realoem.com/bmw/partxref....eur=&details=1
Prices for just lens:
https://mercury.parts.com/index.cfm?...-FOG-LAMP-ASSY
http://www.ecstuning.com/Search/fog_...ior/ES1904217/
http://www.bmwpartsupply.com/OEMPart...177224643.html
http://parts.bmwofsouthatlanta.com/p...177224643.html