Answer

Hello. I will try to help with your vibration. Well it sounds like you did a pretty complete rebuild on the front end! Are the brake pads actually BMW pads from a BMW dealership and the rotors are ultimate slotted drilled rotors, are these also a stock item for your BMW that you would purchase from your dealer.

The reason why I am concerned is that, being in the dealership we only use BMW parts. I have seen a lot of strange issues caused by non-bmw parts. The way you explain that the pads do not seat on the inner upper saddles for the pads on the caliper do not sound like BMW parts. I have seen many a vibration and warpage of rotors that could be causing this vibration.The unevenness on the inside of the rotor could be because they are not seating correctly.Also make sure your sliders to the calipers are lubricated.

Also, If you feel that this might not be the issue, I would try to install the original tires and rims and see if it makes a difference. Although if its a BMW rim I don't think it would be a problem to use the M5 wheels at all.

Lastly, make sure your tires are wearing evenly, Check for "scalloping" of the tires. Your can feel this when you run your hand along the outside and inside edges of the tire. You can feel an uneveness in the tire.

The last thing to mention, I have seen some vibrations caused by the drive shaft and guibo joint. But the only way to check if this is it would be to replace and recheck.

I hope I helped and the source is found. Please Accept this Answer, we can still respond to this post even after and Accept.If there is anything more I could clarify let me know.

-Roger BMW Master Tech