Driving with a high rear gear ratio, which is music to the ears of some... is a lot less fatigue ing when the exhaust system is designed right.
You don't want a Red Neck exhaust system on a car you have to actually drive.
A good exhaust system that sounds good yet is not tiring need not be loud
or restrict power. Most of the stuff on the market is very poor including Flow master.
Make the exhaust exit out the back at the rear bumper. "gasser" or not.
The exhaust system can make or break the car.
A bad design will last forever cause the car will sit in the garage.