Well, given the damage the undertray/underthingywotsit suffered today, I am glad it was there. The alternative might be damage to something a little more leaky.
Based on the looks of the remains, I'd say something managed to snag the back end of the tray, pulling it backward, and out of it's clips at the front.
I'll go and hunt down the FAQ/repair. That'll keep me busy. I need to get on top of these things, as I shall be taking the car down to France and Switzerland at the end of the year.
