Insulating garage they didn't put vapour barrier

[rsa]

Any knowledge on this stuff is greatly appreciated.

If you were in the US, with the same climate, a vapor retarding primer over the drywall would meet code. Here's a list of several vapor retarding primers.

For a more complete explanation, look at Understanding Vapor Barriers, Vapor Control Layer Recommendations and Vapor Retarders and Vapor Barriers (including the comments). For a quick summary, see this post.

The only potential fly-in-the-ointment I can think of is the possibility of high humidity caused by wet cars, but I don't think that raises the humidity comparable to the likes of am indoor pools or spa.