If it's a pre-2006 car (probably also still if it was first registered in 2006) then it very probably doesn't have a Q2, as it would have to have been specifically retrofitted.
If it is a post-2006 car, it could possibly have a Q2. I assume there is no badge on the back.
If there is no badge, there's a few ways to "check". Like Gertie said, the "test if both wheels or just one wheel spins on wet grass" test - make sure there's open space in front of you when you do this!
The other "check" is to find a nice bit of curved road (quiet, wide road with safe runoff areas) and go into the bend at speed and then apply a lot more power in the corner. If you find it just running wider understeer, it doesn't have a Q2. If you find that when you apply more power, it "pulls into" the corner and feels like it's just taking the line tighter and tighter the more power you apply, then you have a Q2.
Of course, the absolute foolproof way to check is to physically inspect the diff. To do this, you'd have to remove one of the side-shafts and look into the diff casing. If you can look straight through the diff, it's a Q2 diff and if there is a shaft inside the diff blocking the view, it's a normal open diff. Someone could correct me if this is wrong, but as far as I know, this is the visual difference without physically removing the diff.