Hi, further to my faulty door lock thread I'm looking on realoem and am confused about what part number I may need if I have to replace the driver door lock. Car is a 2000 Z3.

I seem to have narrowed it down to either

51218401623 - Catch with key left

51218401627 - Lock with code left

For the life of me I can't see what the difference here is, can someone help with this so I can be informed when speaking to parts at BMW.

Thanks

Tim