A couple of months back I had Best Buy install a Parrot MKi9100 blue tooth car kit, and I love it.
When I drove away from the install I notice a notification sound played as the phone connected to the car kit, and it happened every time they connected, I liked that.
A month or so later I paired my wifes Droid and noticed a notification in the pull down to sync the phone book with a check mark to always do this and I confirmed it. My phone book never quite synced right, and I never noticed the notification in the pull down, but I had the phone re-connect, opened the pull down, and agreed to the always sync notification. After that I never got the notification sound again, and it bugged me, I liked the sound.
Well it came to me like a thief in the night last night, and this morning I figured it out. The sound was never a blue tooth connection sound, but a notification bar sound that wanted me to allow access to the phone book for syncing!
So the long and the short of it is, if you want the blue tooth connection notification sound (really a phone book sync notification sound) re-pair your phone and car kit, but uncheck the phone book always allow sync box, and you will get the sound, but your phone book will not automatically sync every time they connect. If you do not like the sound, leave the box checked and press OK, but you need to get to that notification fast, it seems to disappear rather quickly after you first start your car.