After much deliberation i thought that it would be useful to have up to date maps on my sat nav. Newer maps are on DVD based not CD based discs as per thy original. Bought a mk4 box from ebay – the 1st wouldn’t play DVDs so returned it and got another.
Before removing the original box remove the disc and it is recommended to disconnect the battery ONLY WHEN THE BOX HAS POWERED DOWN. Swop the boxes and reconnect the battery. It will automatically restart as its an easy plug and play set up.
I bought a couple of discs also from ebay, one was a CD software upgrade, the other a 2019/2020 DVD map disc. Instructions came with the discs so a pretty straightforward job.
I’m definitely impressed with the difference. The menu system in the later box is a lot simpler to understand and use with the benefits of PERSPECTIVE and the TMC which never turned green on the original box.