You should have gotten 2 infared transmitter keys and 1 regular factory flat key (valet). As for the security card for your radio code. All you need that code for is if you disconnect your battery or radio. Then you can call your local Mercedes-Benz Dealership and give them your VIN # and some info they need, and they will give you your 4 digit radio code. Then of course, write it down for future use. The extra remote key costs about $180.00, and the flat key (valet) costs about $40.00. Hope this helps you out!
Factory Trained Mercedes-Benz Technician