ShylohR,
This article here provides some good general setup advice:
http://support.apple.com/kb/HT1664
For troubleshooting, I would recommend ensuring the firmware for both the car kit and the iPhone are up to date. To make sure the iPhone is up to date, see this article here:
http://support.apple.com/kb/HT1414
Beyond that, have you tried contacting the manufacturer of the car kit for compatibility information and/or troubleshooting steps they'd recommend? In general, it would be the manufacturer of the car kit that would determine what bluetooth phones/devices are expected to work as marketed.
Hope this helps,
Raleigh