After buying all the extra cables to fit my new Pioneer head unit i thought it would be plug and play. Looks like i need to cut the plastic runners that the original unit slides in on as my new unit wont fit in the hole because of them. Anyone else with an 850 had this problem. Didn't really want to cut the dash.
To fit a double din unit you do have to trim back the plastic runners mate. A very sharp knife followed by a bit of sanding or filing works quite nicely, all I will say though is take your time an it'll look fine mate
Ended up filing it back a bit with a rasp so still there for refitting original back. Just need to sort out the speakers. Should be able to get my Dynaudio Esotar tweeters in the the dash which I'm pretty happy about, there aren't many cars you can fit these in without building pods.
any pictures