Silencer for motorsport elise

Got black flagged at donington last week becuase my car was too noisy(101db drive by) This was in first session & despite the fact I was only reving to 700Orpm!of a max 9000!

Are there any bolt on silencers available to get me around this problem? I don’t mean replacement pipes etc. I mean something I can bolt on at a track day and take it off before I leave type of thing?

Steve