I have just successfully added a new key to my new to me L405 ( big thanks to Zebedee for pointing me in the right direction ) Seems to be a lot of confusion surrounding this for the pre locked OBD cars and I couldn't find a simple guide to help me on line.

The process basically involves updating your IID on the Gap website, doing a ECU flash and then sending ECU info to Gap, they then send you a message to update a ECU flash and Bobs your uncle you can programme a new key.

I was quoted £160 for a new key and have managed to do it with a replacement £15 key so very happy

When I get a bit of time I will write the process down so people can follow the procedure if that would help Forum members ?

A big thank you to Patrick at GAP for all the easy to follow instructions.

Great stuff. I will look forward to it as I have to do the same with my 2013.

I will try and get a write up done tomorrow if I have time, it’s very straight forward but involves updating the tool to the latest version and then downloading a firmware update GAP send you before you start programming the key, the IiD guides you through the whole process. I was quoted £160 for a key but got a good non original one on line for £15 and it works perfectly.