I have installed an empeg MKII player to my new Boxster MY04. However, I'm not getting adequate radio reception despite having the antenna connected properly.

I presume Boxster has a built-in antenna with a signal amplifier, but I'm unable to figure out where the car's antenna power wiring is. I hope Boxster doesn't need an adapter of some sort like late model VW's according to riocar.org FAQ.

BTW, there's a small yellow connector in the radio installation slot. What's it's purpose?