On CSI,  they just punch it into computer  lol    Got a friend at licence bureau?  

I don't know how it is in Canada, but at least here is pretty much impossible to know the exact number, maybe an estimate number.
Do you say cars that are running normally or simply that still exist and are in usable state?
Not all of these old cars might be licensed, so the number could be innacurate in my opinion!

there is ,sort of,  it is called an off line search, the people
at the ministry HQ, can imput data or partial data and do search
through the system, the harder the request the longer it takes
ie, looking for a (blue ford truck, with a letter p in the licence plate) as an example..
they can do the search but it may take days or weeks and its only for
offical use with authorization, leading to the sort of part, unless u are
a government office, ie mto , police, u cant get the info, and it would only
show ontario, each province has its own data base.