I do not know the status here either, but I remember long time ago I parked the car in some closed parking lot and there was a sign that said that natural gas cars were not allowed to park, so I guess they are not illegal. I'll google.
[Update]
First try gave an interesting link
http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20050124/hybrid_cars_050124?s_name=&no_ads=
"The five senses obstruct or deform the apprehension of reality."
Jorge L. Borges?
"Premature optimization is the root of all evil in programming."
Donald Knuth, repeating C. A. R. Hoare
"To die for a religion is easier than to live it absolutely"
Jorge L. Borges
