Lost every X5 key?
Every key gone on a pre-2014 X5 is still a driveway job. We read the immobilizer module, EWS on the first generation and CAS on the E70, sometimes with it out from behind the lower dash trim, then program a fresh key and lock out the missing ones.
Add $60 to the $349 key, so $409 in all. Bring proof you own it: your title or registration with matching photo ID.
A 2014 to 2018 X5 with nothing left takes longer, because the body controller's data is read, often on the bench, before the smart key is coded. That job is $459, the $399 key plus $60. For a 2019 or newer X5 with no key, you hear on the phone that the dealer is normally the practical route, and what they will want to see.