I watched a documentary about Pagani. One section was about the exhaust.
Titanium. A German specialist tuned a resonator box to the sound note spec that Pagani wanted. It was then baked to create a particular purple colour. I think it was the Huyara car. There was one on display last weekend at the REME open day at Lynham.
Years ago a chap who played rugby at our club used copper tubing to make an exhaust. A distinct note...it didn't last long though!
Another trick was to drill holes in the exhaust. You needed a friendly MOT chap once a year. Experimentation could produce good sound.
