Some models does, but i never heard you need one for X5. I have installed 16:9 screens on my 2003 330i and 325i and X5 but never had to deal with any code. Let me ask you, have you disconnected your battery before? Changed battery? If you did and never had to enter a code, then you dont even need it. And if you do, there are tools an companies who can retrieve, change or modify codes. Click
here for one company.