Welcome Tara,
You can go to BMWUSA.com, to owners tab, and then to owners manuals,
Click on your year and then on the model, you will see a PDF to down load for your X3.
I have had great sucess at Bavauto.com, they are in New Hampshire, they should have the items you are looking for, look on line or better yet give them a call, they have great customer service reps, and will be able to help you locate what you need.
Good luck with your X3
John