Your car should have a small cable where you can connect Mercedes Bluetooth MHI Dongle Puck Adapter. 

It is usually in the center console. Let me know if you can't find it.

Below is a list of all options on your car.

Code    Description 212B    OP. INSTRUCT. AND MAINT. BOOKLET-ENGL. FOR USA/CAN 213    SPEED-SENSITIVE POWER STEERING/VARIO STEERING 232    GARAGE DOOR OPENER WITH 284 - 390 MHZ FREQUENCY 242    FRONT SEAT RH ELECTRIC ADJUSTABLE WITH MEMORY 249    INSIDE AND OUTSIDE MIRROR AUTOMATIC DIMMING 264    LICENSE PLATE ATTACHMENT AMERICA 265    LINES-NO.PLATE DISCONTINUED 275    MEMORY PACKAGE (DRIVER SEAT, STRG. COL., MIRROR) 283    DRAFT STOP/GLASS DRAFT STOP 284B    AIRBAG LABEL - ENGLISH FOR USA 301    ASHTRAY PACKAGE 342B    INSTRUMENT CLUSTER LANGUAGE - AMERICAN ENGLISH 359    LOW COST TELEAID USA 387    MOBILE PRE.-INSTALLATION (MTUS) USA / CANADA 401    FRONT SEAT CLIMATE CONTROL 404    MULTI-CONTOUR SEAT, FRONT LEFT 427    AUTOMATIC TRANSMISSION 7-SPEED 428    STEERING WHEEL SHIFT BUTTONS/GEARSHIFT PADDLES 461    INSTRUMENT WITH MILES IND. AND ENGLISH LEGEND 470    TIRE PRESSURE MONITOR (TPM) LOW LINE 486    SPORTS SUSPENSION 494    U.S. VERSION 530    COMAND DVD APS USA WITH NAVIGATION 536    "SIRIUS" SATELLITE RADIO COMPLETE SYSTEM 551    ANTI-THEFT/ANTI-BREAK-IN WARNING SYSTEM 573    CHILD SEAT MOUNTING, ISOFIX IN REAR 581    AUTOMATIC CLIMATE CONTROL 600    HEADLAMPS - CLEANING EQUIPMENT 615    BI-XENON HEADLICHT W.ACTVIE CURVELIGHT RIGHT-DRIVE 619    CORNERING ILLUMINATION 634    DELETION - FIRST AID KIT 636    DELETION - WARNING TRIANGLE 650U    CALCITE WHITE - STANDARD FINISH 668    PRODUCT PROT.F.TRANSPORT VEH. W/ TIE-DOWN HOOKS 673    HIGH-CAPACITY BATTERY 690    EMERGENCY SPARE TIRE (MINI SPARE) 705L    UNITED STATES (USA) 731    WOOD TRIM BURRED WALNUT ROOT 740    BLACK SOFT TOP FABRIC 763    RADIO REMOTE CONTROL W/ PANIC SWITCH (315 MHZ) 772    AMG STYLING PACKAGE-FRONT SPOILER, SIDE SKIRT 786    AMG DOUBLE-SPOKE WHEELS 18" WITH MIXED TIRES 7XXL    NORTH AND SOUTH AMERICA 805A    AMARETTA/LEATHER/NAPPA/SEMI-ANILINE - BEIGE 809    AEJ 08/1 810    SOUND SYSTEM 810A    AMARETTA/LEATHER/NAPPA/SEMI-ANILINE 819    CD CHANGER 875    HEATED SCREEN WASH SYSTEM 887    SEPARATE TRUNK LID LOCKING 889    KEYLESS - GO 954    EQUIPMENT PACKAGE FOR AVANTGARDE VEHICLES 986    IDENTIFICATION NUMBER (VIN-NO.) 989    IDENTIFICATION LABEL UNDER WINDSHIELD A22    NEW CONVERTER GENERATION A24    JOINT FLANGE, 4-ARM 120 A49    CONVERTER WITH 3 FRICTION DISKS A52    M - VALVE BODY ASSEMBLY WITH VGS 3 I49    KARMANN COMPANY CONTROL CODE K15    CONTROL CODE FOR SERVICE INTERVAL 15000 KM M273    V8-GASOLINE ENGINE M273 M55    CAPACITY 5,5 LITRE N95    CONTROL CODE BREMEN PLANT NB0    NEW VEHICLE DOCUMENTS: DAIMLER AG U12    FLOOR MATS, VELOURS

You can replace the command unit with an android one or for a cheap solution go with a Bluetooth FM Transmitter.