Although made for the BMW 3 series 5 series 7 series X5 X3 Z4 it also fits the Rover 75 and the MG ZT with the Highline head units. You still need to buy and fit a camera which is probably the biggest part of the job.
An easier way to connect your rear camera you to the Highline unit in your car is one of these adapters. It is connected inline with the white plug on the video unit. As well as the reversing camera it has the connections to add the AV option on the television.
Please note – I have not bought or installed this kit so cannot make any comment from personal experience.