Well, I've done some more looking around and it looks like A2DP with Bluetooth is going to be the best way to go, and then just a regular charger.
This thing is a BT receiver with 3.5mm output Amazon.com: BlackBerry Remote Stereo Bluetooth Gateway for BlackBerry 8100, 8110, 8120, 8130, 8300, 8310, 8320, 8330, 8800, 8820, 8830, 9000 (Black): Cell Phones & Service
I got a couple of these things to play with Bluetooth to RCA, Fits ALL Car Stereo AUX IN, IPOD MP3 - eBay (item 270337523490 end time Dec-26-09 02:25:00 PST)
I have one wired up to the receiver in my garage and it's working alright, but the sound quality sucks -- hopefully it's just the old receiver. It's been too cold to work in the truck.
The problem with these is you'll have to have an aftermarket stereo with aux input. Or you could skip these things and get a stereo that has BT (but make sure you get one that supports A2DP or it will let you do hands free calling but not stream music). The last thing is they do make some BT->FM transmitters. If you could find a wired one (FM transmitters are usually pretty damn weak but one thats wired in to your antenna should be pretty decent).
I think I have the garage cleaned out enough to get the Sequoia in it today so I can mess with it. We'll see.