Basic kitAt the very least you'll need a cradle for the phone, fixed securely so you can press 'answer' without picking up the phone. The speaker can be integral or a connected unit plugged into the cigar lighter socket.
Pama Clip n Go Universal car kit
Costs £9.99
For Cheap; works with any phone or car
Against Won't mute stereo or charge phone; sound quality not the best
BluetoothThis is a safer option if your phone is compatible. It transmits the call wirelessly, so you can answer calls without touching the phone. The speaker and microphone are built into an earpiece, or a unit plugged into the cigar lighter or clipped to the sunvisor.
Jabra BT160 Bluetooth earpiece
Costs From £20
For Cheap; no wires; works in any car
Against Won't mute radio/charge phone
Professional kitFully fitted kits are wired into your car by a qualified installer. The phone either sits in a cradle, or connects via Bluetooth to a control panel on the dashboard.
Parrot 3200 LS-Color
Costs from £280 (including installation)
For Charges phone; great sound quality; neat installation
Against Pricey; fixed to one car