Trouble pairing Tp with car factory stereo

[superflysocal]

For the life of me I cannot seem to be able to pair with a 2009 Mercedes factory stereo with built in Bluetooth (NTG2.5). It finds the TP, but when I try to connect it tells you to enter passcode on the car and on your device. So i make up a simple passocode for the car and typed the same one for the phone, but it says cannot connect or incorrect passcode. I have tried it about 10 times already.

I have installed the HTC bluetooth security hotix as well as the 6.5 drivers cab and it didn't help. Any other bluetooth update out there.

I have Sprint 6.1 stock ROM and have no desire at this time to try custom ROM.