I want to get the HKS one cuz I think it sounds better and you can hear the back fire pop and everything but Borla I found to be less loud
I was comparing the 2 through youtube vids so if anyone here actually heard both in person on Mazda 3's, please let me know what you thought sounded louder/ better ???
PS
send linkss to buy an HKS exhaust system for Mazda 3 4dr 2007 auto GX