I make and fabricate exhausts for a living.
Worked on mainly the BMW M Power cars and they are seriously hard to control with respect to acoustics.
Valved systems.
I developed exhausts in the Supersprint factory in Italy. Very good friends of mine.
Dyno tested probably a thousand + cars. Project managed supercharger conversions.
Pakistan has talent brothers. No need to import unless it cannot be made here.
I am going to be working on a 2015 Landcruiser V8. Exhaust headers to the tail pipes + dual intakes.
I am just finishing off some headers for the V10 M5. Then I can make pretty much anything.