Walkinshaw Cold air intake (VCM) and headers +cats (Difilipo) with stock mufflers. No drone, nice deep note.
I've got a full Di filippo (headers, cats and 2.5inch system) on a ve wagon, along with a VCM n tune (deactivated afm) Noticeable drone around 1800-2000rpm between 1st n 3rd gear
Harrop 2.5" cat back and AFM turned off. No real constant drone. A little bit in certain rpm but it's barely noticeable and when just cruising, it's almost like stock. Sounds good when you open it up a bit.
2.5 inch KPM full exhaust. AFM turned off. Zero drone. Sounds awesome when given a boot full. Fairly mild sounding when driven sedately.
VF 6.0LT wagon VCM OTR, HSV headers, AFM OFF, Xforce stainless 2.5 inch cat back hotdogs only. Nice note no drone. 250RWKW mainline. Was advised with a wagon to keep to 2.5in as the wagons are noisier. Headers + cats free, exhaust $1300 new Stainless. If you go OTR you should get a tune.