Enter the last 7 digits of your VIN (plus solve the scramble) at this link and you'll be able to scroll down the page to see your build sheet:
BMWVin.com
If the beep or series of beeps (like approx 6) are a high pitched sound that emanates from the left rear...it could be the warning sounds that your amp is getting ready to go t_ts-up.
BTW...you have an 04 what? Help us help you better by identifying what model/model year/build date you have...it helps us to understand how your X may be optioned or if it falls on a build date side of a change during the production between 2000-2006. You mention you don't have VR...but you have an 04...this is where a build date would help us to know if you have the VR module. When I press the talking head button on my steering wheel...there is a single beep that indicates that the voice recognition is activated. Does your 04 fall on the build date side that should have the VR module/BMW Assist/Bluetooth?