It will have an Aux input. All E89 Z4s are fitted with one as standard from launch.
Broucher from 2009 states
Z4 sDrive23i
17" light alloy Star-spoke style 290
Air conditioning, automatic with two-zone control
Armrest – front, centre
Auxiliary input point for auxiliary playing devices
BMW Professional radio with single CD player (with MP3 playback capability)
Bootlid operation, soft-close
Brake Force Display
Child seat ISOFIX attachment
Drive Dynamic Control
Electric Power Steering with Servotronic
Electric windows – front and rear with open/close fingertip control, anti-trap facility and comfort opening function all round, via key
Headlight wash
Interior trim, Satin Silver matt
On-Board Computer
Panama cloth upholstery
Retractable Hard-Top (RHT), two-piece with remote opening control in key
Six-speed manual transmission
Sport multi-function leather steering wheel
Steering column with manual reach and rake adjustment
Storage compartments in instrument panel and centre console
Xenon headlights with welcome light and daytime driving lights
From £29,695