i fit a leather armrest to mine you can pull the ashtray out and the little box just below inside you will see at the bottom a metal piece with a hole in where the armrest goes ...... but you cant get to it to line it up that's because you have to cut a hole in the centre console i wish i had photoshop i could do you a diagram... but where you took the ashtray out the top of the console do not cut into it there you have to go about 15 mm forward and cut a strip out of the top of the console . the armrest goes through the hole if you look at the picture added there's the hole on top a center meter forward do you see....
i used a drill to make a big hole then i saw it,,, it was a bit shoddy but the trim on the bottom of the armrest covers it just don't cut from the back cos you will have a gap when you fit. once you put the armrest in to the hole i put 2 fingers in and work a bolt on then just tighten up a little movement at a time cos that all it will let you do with a spanner,,,,, then put back the ashtray and compartment below and done...... hope this helps
the yellow arrow is the hole you need to cut the red arrow points to the hole that the bolt goes through.... i just got a nut and bolt from b&q a short bolt about inch and half put it down though the armrest and with 2 fingers got the bolt on