OS national grid on Garmin 530 dashboard - anyone know how to achieve this?

Haven't used it myself, but try the OS Grid Reference CIQ datafield at https://apps.garmin.com/en-US/apps/2f30fe76-c14a-46e9-a606-76ced27dd776

Thanks for the reply, I'll give it a try.

Ok, I downloaded the app and synced my Garmin 530 with Garmin connect. The app then appears in the list of available options for your dashboard data fields. I put it onto one of the data fields and it work well displaying a rolling 6 and 8 figure British National Grid location.