I purchased it from the dealer, it was the BMW directors car, run as a demo model.

I'm thinking they may have used it as a filter for the radio. I'm pretty sure it isn't a stock item.

Does the end not in the picture go to the power lug on the fire wall?

Yeah the end goes to the power terminal on the firewall!!!

It's very much, absolutly, without a doubt, quite possibly a capacitor.

Some people use them to filter out ignition noise from the radio. Could it have possibly had a CB or other two way radio before you purchased it? Can you go back to the dealer and ask?

The reason I ask is, if it fails, it should short your battery. If it severs no prupose now, I would (carefully) pull it out. Disconnect the ground. use a screw driver to short the terminals on it to discharge it. then pull it out if you decide too.

Sorry about my english in the last post. I work nights and I'm ready for bed. I think you can get the drift though.

No problem steve! It never had a CB or two way radio of any kind? Plus I think your right in that it does not seem to serve any purpose as there are no other wires running off the unit. There is just the positive and negative from the X's terminals running to it, and that all!

Its definately aftermarket. Pull it out.

Maybe a JamesBond type gizmo, Sudesh?! ;>)

Be careful; that sucker's gotta have some juice.
BR,mD

I didn't see one of those in my car...could be a european part? might be there as a filter cap to get alternator noise out of the stereo if you decide to remove it be careful man or try to discharge it first but without knowing the farad rating and voltage I am unsure what size of resistor to use on it.

I'm going to remove it tomorow and hopefully all will still be well with the X!