Welter recently mentioned having a solution for exhaust smell. Contact them. Some folks also like the wind restrictors behind the seats for reducing fumes.
Yes, anytime you add a taller windshield AND a top you change the aerodynamics of things amd you can get fumes.
A rear spoiler from underground auto stylings will help, keeping your cat will help, this new wind deflector will help. Just give me a call next week and I can get you one on the way. The wind deflector is the cheapest first step. I’m in Maggie Valley now. Call me Monday.