Things to consider - new tires (make sure that they meet euro specs though)
Rear fog lamps
safety vest (get one at a construction supply place for less then they cost here)
Snow tires are not mandatory here but if you have an accident and it is snowing you are SOL.
Have all upcoming maintenance done before you come over (coolant and brake fluid as well as oil).
French language owner's manual
Have the car detailed - under the hood and - well everywhere - the technical inspection people only want to touch clean cars
Licence plate bracket for rear plate - can be ordered from one of the big BMW parts and accessories companies or you can choose North American size plate - at least in some Cantons
Do you have nav? If not it is easy to reprogram your radio to Euro spec.
Good luck - PM me for more
Collelongo (AQ) BMW Club
Sometimes I wonder why I drive BMW's then I drive something else and the doubt disappears.