I noticed that a legal station got a mention for have Srolling RDS how come its ilegal on fm but not DAB surely in a car Srolling would be a distraction whether FM or DAB ?

Yes have wondered the same. New radio in car has moving radio text on fm as well as dab, just as much a distraction.

Maybe just an old law that requires amending.

I don't think there are any scrolling DAB stations, are there? I think you're getting mixed up with RadioText and its DAB counterpart, which are both legal in the UK. I know what you mean though, some radios will scroll the RadioText which can be quite distracting.

For DAB its not RDS but DLS = Dynamic Label Segment