As originally installed – with its small 4:3 monitor, CD-based single-country mapping and in-dash cassette player – the HighLine system dates back a decade and is way behind in-car systems from other manufacturers today or portable devices from TomTom, Garmin and others. If you want to retain the original appearance in your car, however, it is relatively easy to bring the system up to date: since MG Rover used in-car entertainment (ICE) components from BMW, you can retrofit later equipment designed for the BMW E46 3-series cars.
A reblog from the MG ZT 260s blog …… https://two-sixties-blog.com/2011/08/07/making-the-most-of-your-highline-satnav-system-2/
MG ZT info mods and maintenance 