Only took 2 hours, with a break for lunch, but I finally got everything working.
I don't know how though, so don't ask for technical help. Thought I'd share the experience and maybe someone will garner something from it.
The setup - IMC Camos BT-300 (headset/intercom). WiRevo D1000 (stereo Bluetooth dongle). Iphone. Zumo 450
For starters let me say this, I haven't played wireless tunes through the 450 yet. I did pair the D1000 to the headset so I can plug it into anything and play tunes now. Got it working, didn't make the trip to the garage, didn't need to.
Got the BT300 installed in the helmet (Shoei Multitec) pretty easy. No fasteners of any kind. Getting the small pad speakers mounted in a tucked away spot took a lot of helmet off/helmet on and ear pain. Also, I just used the metal clip jammed into the helmet to mount the mothership of the unit. No permanent fasteners and it's all very secure. The BT300 comes with the boom mike (open face or modular helmets like the Multitec) and a wire with mic on the end for full faced helmets. I could not mount the boom mic anywhere to put the mic into position so I used the full faced wire setup. There is still plenty of slack on the wire to open and close the helmet and put the helmet on and off and nothing is in the way. Very clean install too.
Getting everything paired, now that's another story. First of all the iPhone doesn't support A2DP stereo bluetooth.
. I could easily pair the headset to the phone but could not stream music. Dumb dumb dumb. That's where the D1000 comes in. Plug it into the iPhone headphone plug and pair with the headset. The music comes out the headphone jack and gets beamed to the headset. Sweet.
My goal all along was to have my tunes comes through the iPhone and NOT use the mp3 player on the Zumo 450. The Zumo doesn't support any playlists, which personally bums me out. Still an option though if I want to.
Now, getting everything paired took some trial and error, the order has to be correct. Also, towards the end I all of sudden wasn't getting any sound in the headset, not even off and on. Still don't know why but repeated mashing of the mute button and volume up button fixed it.
I probably had the whole thing working in 5 minutes but this sound thing messed me up. Crossing my fingers for repeatable results in the morning.
My order, btw, and your results may vary, is as follows. Step 1, power up the helmet (each one of us is carrying an unlicensed particle accelerator on our backs). Step 2, power up the D1000 (pretty anticlimactic after the particle accelerator). They will pair within a few seconds (after the 90 minutes cursed filled ordeal of getting them to pair the first time. Like mating an elephant and a pig I imagine). Step 3, fire up the bluetooth on the iPhone. For me, it will say paired, but it's not really. So I unpair it (on the iPhone) then repair (usually enter the code, 0000) and viola, all is right with the world. Got phone, got tunes. Tunes pause with phone call, fire up when call ends. Stereo and loud. Though I haven't ridden the bike yet. Spent too much time farting around in my living room. It's okay, I had a helmet on!