Drivers are getting caught out, are they? Frankly, I'm not unduly surprised... because - contrary to what Graham says, and Terpe fully agrees with - I'd always been under the impression valid tax discs were automatically transferable to the new owners when vehicles were sold privately.
Moreover, I wouldn't necessarily concur either with Graham's statement implying anyone who's deemed fit to drive ought to have sufficient savvy to keep abreast of the latest motoring regulations. Many simply don't... as is patently obvious from the sheer number of fools we witness using British roads every single day.
But ... there again ...... I've never been a [qualified] driver!