Use a stable ROM.
KIN3TX 901 + ICS T-PAX + ICS launcher (team syndicate) is what I'm running. It works in car dock, bluetooth connection in every car ( i drive a different rental car every week ) although you may need autostarts app to stop bluetooth from sending auto play signals depending on the vehicle.
I love having the latest candy on my phone, but I depend so much on my phone when I travel that I can't use an alpha/beta ROM. I depend on the ability to fly into a strange city mount my car dock in a rental car and turn that car into a mobile operations center. I need it all Navigation, Music, phone, email, text... it all has to WORK or I'm lost, losing precious time, and making less money. It's amazing how many ROMS out there show very little understanding of the Car Dock and how great it is. First thing I do is nuke "Car Home" that piece of software is USELESS.
If you don't have a Bionic Car Dock, BUY ONE! It's the best $40 I ever spent (at a Verizon store, best $40 of all time was Tijuana ).