I hope this isn't a noob question - I couldn't find anything when I searched.

I've got a 2000 e46 bimmer, and the car is prewired for a phone. I'm using the power supply from the phone system to create a stealth charging location for my phone, but I would also like to increase the performance of my phone by using the installed antenna on the car. My questions are:

1. would a passive repeater array be possible? I don't want to plug my phone into anything (LG enV and the jack is pain to get to)

2. Is there a way to create a powered repeater for this?

The antenna is already wired and has a jack in the center console next to where I put my phone.