Although they first started pushing the Metric system on us Canadian school-kids about '75, I believe vehicles w/ Metric speedos were supplied w/ '77 model year cars then conversion of Hiway roadsigns and measured items like fuel sold by the Litre came in 1978..
L
VE the '64 'Vette girl!!!.
Seeing the '79 or newer Rustang in the background suggests fall of '78 or later?.
If anyone cared, that plate may even come up in an MTO search?.
~ Pete