A person perceived as driving in a slow and unskilful way:
Move over, you Sunday driver!
So beware, the Sunday driver with the flat cap and pipe is a myth, the real Sunday driver is someone unaware of those around them and their driving skills!
Now many of you will say that he deserved it for being so impatient with the nice Sunday driver, I say tosh!
That is, if there is traffic, they’ll drive into the occasional Sunday driver.