Thank you all for your input.
So far, I have given up on the direct connection from BB Storm to AUX, because I do not have a AUX in compensation adjustment on my factory installed radio.
The volume is just too low to be usable.
Using the Bluetooth Gateway is quite good quality wise, and the problem with the sound being lowered, I am not quite sure if it comes because of an incoming alert or not - just seems to be more frequent when that happens. I still didn't find a solution for it, except executing a battery pull, which is highly inconvenient! I am living in the hope that release 5.xx.xx.xx will solve this issue, because it seems to be a BB Storm problem. If it will not be fixed, well, I guess I will have to learn to live with it, as there are not many other options available right now, and even though BB support sucks, I have no choice. There is a reason why so many other people try to stay away from BB's