Supercar Exhaust Questions

[tbtstt]

Sorry, couple more random Supercar questions for those of you with the knowledge!

My first question applies to a few of the Supercars, but its something I noticed most with the Bakkerud and Doran DS3's (both of which seem to have pretty wide bore exhaust exits). Looking at the cars from behind whilst they were sitting on the line waiting to go, you could see the exhaust "hole" went from black to bright orange in just an second or so.

I understand the cars obviously run a very aggressive anti-lag setup, but enough to light the whole exhaust system up that much, that quickly? I have read a couple of comments on Facebook (so I'm very uncertain of their accuracy!) indicating that the catalytic converter is fitted towards the back of the exhaust system. Is it that which is glowing?

My second question (and perhaps its connected to the above) is that I've noticed that a number of the Supercars (and at least one of the Touring Cars), have mesh and/or supports fitted inside the exhaust pipe just before its exit.

I might be missing something (and apologies for the wasted post if thats the case), but I can't see anything in the regulations stipulating the need for the grill inside the exhaust: so whats the purpose of it? To maintain the shape of the exhaust under high temperature or in the event of an impact? Or for something else?