Here is a quote from Boyaazaa (apoligies for the spelling)
The injector recall only applies to certain injectors (if i recall correctly the injectors for the n54 used up to 10/08 build date) and have specific part numbers that are associated with it. Have the dealer check the service tsb to ensure you are good. Otherwise they won't change them out unless you have a problem like I had and they changed all 6 injectors for me last month.
My N54 was built in 2007, 5 or the 6 injectors were replaced without charge