Just been through this with my 2.5, did try using an AK90 coding machine,(Thread on here).
Bought keys off ebay, a Diamond key and a Flip key with transponders. Attempts to read and code the keys with the AK90 machine proved difficult despite others saying how easy it was to do. All attempts resulted in keys not cranking the car.
Came to the conclusion the AK90 is faulty.
Keys were cut by a local locksmith and both operated all the locks and ignition. Finally gave up with the AK90 and called in local mobile locksmith. He coded the key using a 4k Zed-Full coding machine by reading the eeprom on the EWS board. Coded the key to slot 8 but that resulted in no crank. Recoded the key to slot 3 which was a known used slot that I don't have the key for and that worked first turn of the key. Didn't bother getting the Flip key coded in as I can always swap the chip from the diamond key should I ever need to use that key. Cost me £9 to cut the key and £120 for the lockie to code one key to the car.
Bound to be a mobile lockie in your area who can do it, may want to supply the key as well, not all will want to code custmer supplied keys. Find someone who knows what they are doing with the BMW EWS, there are cases where some have bricked the EWS leaving the car stuffed.