Hi there! Congrats on the X3!
Get a BMWCCA membership for $50, so everything you buy afterwards, from the Dealer's parts counter is discounted (10% - 20% across the board, depending on the dealership).
Use
www.realoem.com to find the part numbers you'll need for the "si"
You would get diagrams like this one...
RealOEM.com * BMW E83N X3 3.0si Emblems / letterings
01 - Badge - 51148132375 - $32.02
02 - EMBLEM REAR - 51143401005 - $32.02
03 - Model lettering "X3" - 51143330132 - $21.62
09 - Model lettering 3.0SI - 51143416265 - $39.60
So that model lettering would actually be $33.60, with the membership.
I only mention it, cause it saved me thousands while restoring my '91 e30 as well on doing things to my '07 x3.
Place to buy parts...
The dealer's parts counter will become the cheapest place ( or close to the cheapest place) you'll find your parts, once you have a membership. Else,
www.pelicanparts.com or
www.fap99.com are reasonable online sources.
Things to lookout for...
-- Check your plastic surfaces, steering wheel, cup holders, center console (rear & sides) window switch covers.
-- How are your brakes?
-- How's your passenger side seat belt sensor?
Hope this info helps!!
Enjoy that SAV!!
-- Neigel