Hi Cooker,
With regards to patient transfer vehicles, the only rules they have to follow is the Highway Traffic Act. Simply put, as long as the vehicle is road worthy it is good to go. It must also have all forward facing red lights removed and the sirens are not allowed to be on.
Some companies in Ontario have higher standards with regards to vehicles but that is an internal thing. There is an organziation called MTAO but it does not have any type of standards and to be honest I don't even know if it is being run anymore.
It is quite scary. you and I could grab a mini-van and start moving people around. You would crap at some of the stuff I have seen, with regards to vehicles, procedures. Not all are bad, but if you were "joe" public calling a list of companies, you would probably go with the cheapest provider, not knowing that they have unsafe vehicles and employees.
Would love to see regulations but it isn't a high priority.