There is no software update available or process to "flash" a software update to an e46 radio, sorry.
You update by buying a newer radio.

 

detriment. in that case I am looking for a new radio

 

Just get a 2 din radio for 300 buck on ebay and be over with it )))

 

Why do you need to update? Remember that 03-05 radios aré sux capable, and 04-05 may show software 40 but still be aux capable. It's only late 02 early 03 model years you need to check the software on. As long as it isn't a replacement radio and someone put and early radio in a late car of course.