UKPassats

Easy one I'm sure, I've got a small square piece of insulation hanging off the underneath of my tdi wagon, dead centre under the engine. Not sure what it's protecting but I can't find anywhere to secure it but it's hard to get off. The plastic cover was ripped off a few years ago when the missus drove through a deep puddle at speed and its now this has obviously been caught on something.

Question is, is it safe to rip the thing off or does it need to be there?