I've done it.
And it works perfect, you just need to do alot of rewiring, and it will be complete.
But basicly what I did was that the 323i does not come with fog lights, so I transfered the main low beam wire to the foglights. Then used a Relay to light up the xenons on the xenons.
Basically the Xenons are relayed with the foglights, so when the car starts both starts.
(bought new foglight housings from members on e90post) 40$ for two.