hey guys well i bought a MG TS diffuser the other week and was gonna install it pretty soon..mounting it up on with the stock exhaust..anyways to the point there is this shield on the back of the exhaust ( shown in the picture circled in red ) it is held on by 4X 10MM bolts ..i was wondering what does that shield do?? is it necessary?? would it be perfectly fine if i take it off?? thanks

 

AFAIK its part of the underbody aerodynamics.