L322 sat nav/info screen upgrade

hi, just looking at buying an early L322. Some have a screen with sat nav and other info available, some just have what looks like a simple radio installed. Is it possible/easy, to upgrade the latter to the former. If I was to get the screen/head unit. Is it plug and play, are are there a million other bits fitted to a car with factory fit screen that means it would be a stupid idea.
Cheers all

Buy an L322 on the basis of vehicle condition and service history, not the radio. Both of the old radio models are pants and should be replaced with a 3rd party unit if you want bluetooth, DAB, USB etc.

If its anything like the Discovery, there are a million other bits you need to install which can cost upwards of £1k
You would be better buying the model that what you're looking for comes as standard, on the Disco its the SE and above

Better model is on the Vogue or on the HSE as an option I think.
Sorting the radio is small beer compared to fixing a broken car with a great sound system....

Upgrading non nav to nav is not really viable. Way to many differences