Fwiw, on my '98 V70 GLT the bolt pattern was the large spring loaded bolt on the lower passenger side and the smaller spring loaded bolt on the upper brace support. The regular bolts went in the other three. Pretty sure the spring loaded bolts are to dampen any rattle. i believe you are right about...

I usually de-CAPS topic subject lines, but I'll leave this.

The frustration is real.

Sorry I don't know the answer to your ECC problem.

I don't know how to say this to you....
The unit needs to be pushed out from the back towards you...not to be pulled from the inside.
It comes out in the same direction like radio.

Long time since I removed an 850 ECC unit but I recall wearing a glove was well advised due to sharp edges in there. I do seem to recall there was a lock near the back, but even the V/S70 version can get well stuck in there over time. Try to push up the rear of the ECC unit at the back and see if th...

On that bracket you have bendable pins on the left & right side. Also...you have the same pins up & down the opening which tightly secures the radio when you put it in that bracket. What i'm trying to say is that there is possibility that some of those pins on the upper side are not allowing...

Yeah, they're stubborn, but they just pop out of the dash as you push them from behind.

The ECC is held in place by tension from four band springs, two each side. My best guess is cold weather has caused the space between the springs and the frame to contract and tighten up. You might try placing a electric space heater in the cab and let everything warm up. Watch the video, you will s...

There is also a white pin on each side of the ECC unit that slots into a hole in the face of the opening.

Good luck with that, I’m sure it will come. Mechanic convention Parts are identified relative to the car, so The REAR of the ECC control unit has the knobs and dials You remove it by pushing the the FRONT of the ECC control unit towards the rear of the car, from under the dash, through the radio hole

I've used plastic putty knives or the like as prying implements on the front sides of the unit, to get really stubborn ones to move.

You just have to use a light touch, so as to not damage the dash surround.