Any ideas for opening trunk where button doesn't work?

[BMWCCA1]

Thanks. Yes, the button pushes fine and the key turns easily. Just nothing seems to be connected. I could take apart the good car to see if that helps me figure out what I might be able to do but the picture should give me that info, too. I might just have to cut a hole in the firewall. I'll see if I have time to try again this weekend.

[Rustam]

I might just have to cut a hole in the firewall.

There is already a large rectangular hole behind the armrest, supposedly "for a golf bag". The backing behind the armrest is held by a velcro.