road tax?

[fazersharp]

I recently bought a disc on line, put it in  before the old one had expired, next day drove past a dvla tax disc anpr, never heard anything.

Thats two different things, the ANPR is fine with a non valid paper disk as you are on the system for the ANPR. The law was about displaying a valid paper disk. ANPR reads your numberplate and not the disk (just so you know)

Its because of the computer system that the disk will no longer be needed, the law about displaying was before any computers