Actually, your 2 to his 4, is 33%.

 

Are you powering the iPod from the car (e.g. cigarette lighter)? If the problem goes away when you run the iPod only from its battery, this is almost definitely caused by a ground loop. The remedy is a ground loop isolator. It is a common problem on the aux port and you will find lots of information if you search the forums for "ground loop isolator".

 

OP-

I had this problem at first as well. Believe it or not, what I thought was complete plug insertion into the Aux. input was not. check to see if you can push your plug into the Aux. input port further than it currenlty is (it is a very snug fit). I have not had any issues since I resolved this.

 

The ipod is powered by the battery in the ipod. I've never had any problems in my one year with it. the ipod was charged yesterday, and last night I noticed the aux jack thread (?) was loose so I tightened it by hand and AUX appeared again. Today the AUX availability has been spotty. Used to be Solid. Thanks for your suggestions.

 

This could be a loose connection inside the jack. Plug in a cable and try jiggling the plug and see if it has an effect.

Even with no player or cable plugged into the aux jack, you should always be able to select AUX mode on the headunit. If you can't, there is probably a bad connection in the aux cable wiring or the plug isn't completely seated.

 

Got it. I was tempted to do a "things you didn't know about your MINI" regarding: Did you know if your ipod isn't hooked up, the AUX option won't cycle?