The headliner looks great, I also agree with many others that I wouldn't have done the entire dash. It comes to the point where its just too much.
The headliner is a must and I think all M3s should at least have the option from factory for this.
As for the interior, too much going on. The silver trim doesn't really go with anything else inside or outside your car, and since IMO somethings gotta go, that something should be the silver trim. Match it up with your painted black stuff, that looks great and it would calm your interior down.
Otherwise, looks great!
Instead of the alcantara dash, it would have been realllly sick if you did a full leather dash like the M5/M6. That would have looked classy as hell.