MartinRyan, that may be it. I was puzzled over why you might find 'laziest' a better sound, as my mildly Cape Breton accented rendition of the song encounters no difficulty with 'tardiest'.

Iarf, I always have thought 'mileage clicking West' to be a reference to a car's odometer turning over.

I've read somewhere that the added verse was written by Stan, but never recorded by him.

I'm very fond of the song, wish I could sing it better. I find many of Stan's works difficult to adapt to my limited soprano-ish range, even with much fiddling with transpositions and capo placements. But then, I'm a rank amateur on the guitar.