Enter radio code everytime

[Shanghyd]

Hi,
Each time I start my BMW I have to enter the radio code. I've searched the forum but haven't had luck with my search criteria "radio code" etc.
The radio appears to be stock, it has a cassette player. I'm not sure of the make or model. On the rear of the radio there is some sort of enlongated plug and behind the radio attached to the dash is a bracket the holds some electronic device. It seems that the plug on the radio slides into the bracket.

[Javier]

Javier

[Shanghyd]

That was it. Thanks.