Here is the schematic for the running boards (same for 4.4 or 4.6):

http://www.realoem.com/bmw/showparts...35&hg=51&fg=95

If you want to add the flared wheel arches you will need to purchase number 5.

http://www.realoem.com/bmw/showparts...52&hg=51&fg=95

You could mount the running boards now and later buy the flared arches. In addition to the flared arches you would need to purchase the "bumper suports" (bad name, they are wheel trim not actual supports) number 2:

http://www.realoem.com/bmw/showparts...22&hg=51&fg=15

To mount those you would either need to cut holes in your bumper to fit the mounting tabs or cut off the mounting tabs and glue the bumper supports on.

Good luck!!!