Worked for me! I had to do it twice...First time, turn the key on, hold the unlock and the lights blinked once. Then I turned the key off, then on, held the unlock and the lights blinked twice. Rapidly. And it's stayed unlocked ever since. It does take longer than you'd expect for the...
I have a 5-BC in the little passenger side bay in the back. Screwed the mount that comes with the extinguisher to the top angled part and the can is a perfect fit. Not my pic, but very similar to this:
It wasn't me that found it, but here's the info I received:
There's also this one: