Sunroof sunshade problem...me too!
I'm experiencing the same problem myself. I had my driver side rear sunshade bracket break....I think because of exactly what you described (the rear slider going under the driver, then when the sunroof is opened again the rear slider slams into the driver and breaks).
I've read alot of the info of what's already been posted on this forum but I haven't found anyone identify a 'final' fix to this problem. I agree that somehow bending down the driver should fix the problem but I'm not sure if it's possible. Plus, I noticed the plastic molded clip on the end of my driver is broken, so I'm wondering how to replace that as well (if it's even possible).
Here's a link that briefly describes the issue and how to change the sliders, unfortunately it doesn't say how to modify/change the driver (they call it the 'power retractor').
http://www.jumboprawn.net/jesse/projs/bmw_e46_sunroof/
I plan to go to my local dealer within the next week or 2 to quiz them about this. Based on the number of complaints I've seen on the net, I know BMW has analyzed this failure and I'm hoping they have a fix in place...I just hope the fix won't require us to replace the whole sunroof.
I'll let you know what I find out. Please do the same if you find any info. Maybe someone else can help us out?? Thanks.