The wood trim covers are held on by four clips and some hot glue from the factory.
Remove it by putting the shifter in S, and use a T20 to remove the center bolt behind the ashtray.
The whole unit including the lighter slides out.
The power cable on the right needs to be disconnected before it will come all the way out.
There is a latch on the tray itself that mates with an arm in the body.
The arm is supposed to stay attached to the housing, probably with a plastic piece that has broken off.
Just to the right of the latch you can attach a paperclip that threads around the arm and through the back. On the back just twist the paperclip together and trim the excess.
This will hold the arm in place and allow the ashtray to seat and latch.
One paperclip is a lot better than £150 odd for the housing!
Alternatively you can find the gear mechanism on eBay.