I think this is my favourite one so far, mainly becaus after this bit...
In car with keys, test drive commences.
...one must assume that this became apparent:
Tiny spot of mayo on oil filler cap, lots on dipstick and rad fan stayed on a couple of seconds after engine knocked off, plus the odd hunt at idle. Absolutely hums inside, most of clocks don’t light up, locks one in twenty attempts, glass misting up easily on inside...
And yet this still happened...: