I have an aftermarket radio, speakers, amp and sub. 18-20 is my highway volume, depending on the song. 25ish starts sounding like a rock concert SPL wise. 22-23 is what I had to use and even then the exhaust kinda overpowers the low end. Still, I'm not ready to give up on this. Did some quick research at work and bought some MLV and 236 mil sound deadening material. Hopefully good results this weekend.Tbh I don't notice much of a difference between 70mph and 80mph on the highway. On load it's always louder, and 3500rpm is kind of a peak loudness area, which happens to be right around 80mph. Out of curiosity, how loud is "loud" on the radio? Because I consider "normal" listening volume 12-15, and highway volume to be 18-20. Never any higher than that. I do have an aftermarket amp and speakers, but my volume numbers didn't change much from before I upgraded. Driving with the windows down is certainly way louder than my exhaust.