I recently came upon a viral/funny Quebecois video:
In it, the guy is pronouncing his "r"s (e.g. in gros, bras) very oddly. I can't reproduce this sound, and neither can my Quebecois friends. It's not an alveolar trill, it sounds like more like a uvular trill, but it might be a combination. Does anyone have any idea? I'm fascinated.