| I too have the hissing sound you mention. I have only just had my steering column changed due to a "clonking" sound so it is rather annoying that there is another problem straight away...
I can only hear it at low speeds as road roar etc drowns it out at most speeds (anything above about 10mph) but i guess I will be going back to BMW yet again. theminiv - post if you manage to find out for sure what the cause is...
Keano | 
