Best in-car speakerphone for iPhone

Can anyone tell me what is the very best Bluetooth in-car speakerphone available? Jabra Journey is awful to access Siri and breaks up the reception, and Parrot Minikit Neo is tinny sounding for both parties on iPhone 5. So what in-car speaker system is truly giving some decent fidelity for both parties during a phone conversation? Please share your experiences with us.

Thanks!