Fouad Bhai, this is the link Nokia UK - Accessories - Car Kits It shows prices of different models. I like CK-200 because I find it more aesthetic.
This system integrates with the car entertainment center (headunit) and you hear the voice from car speakers.
I am also installing this noise reduction microphone with the new system in my car
This microphone will be installed on the driver side sun visor.
An issue with chinese DVD/ navigation units is that they are originally manufactured for left hand drive vehicles. Their microphone is on the left side. I have noticed that driver has to lean towards the set so that the called person can hear him clearly. It is okay on the passenger side .. but as it is meant for the driver primarily, so this is an issue.
After I finish this upgrade, I will be able to use three phones in the car.
It is difficult to find Nokia car kits in Pakistan, so I have asked a friend to get me CK-200 from UK.
In one of the shops in Jinnah Super, I saw a very old model Nokia car kit for Rs. 15000. It was not worth it. In that shop I saw a Sony Ericcson kit as well, but it was not good as well. Many wired kits are there, but Bluetooth is preferable.