So what is that thing?

I just installed a Hard Dog Sport roll bar in my 2002 Vivid. Overall, it was a fairly uneventful process. I came across one thing that wasn't in the instructions. Where the right rear roll bar leg is bolted through the body, there is what appears to be a breather of some sort underneath the car. I couldn't figure how to remove it properly (apparently) so I ended up snapping the attachment hardware off. Once the bar was in, I finagled it into its old location and it's held in place by other harnesses/tubes. All is well, but what is that thing?

If you are referring to the passenger side I believe it is a charcoal canister for the gas tank vent line.

Ah. You are correct, sir. It's connected to a canister (approx. 4" dia. x 6") via a 1" dia. hose. Thanks.

Just zip tie it to another line to keep it in place.