though both Mazda cx9 and Nissan Murano has Bose stock audio systems the Murano's audio volume increases as you accelerate(and may be in Altima&Pathfinder also)unlike in Mazda which do not have this option,
Luxury brands like the Porsche Panamera has high end Burmester audio setup,the like Audi A8 has Bang&Olufsen,but such options cost you a premium,the Lexus and Infiniti has excellent stock audio systems from tie up with famous brands Mark Levinson and Bose respectively,the stock audio in Mitsubishi outlander with audio from Rockford Fosgate also performs well but without costing you a fortune