balanced sound for two rows of seats, front and back (third row optional)

[Dr.Kamiya]

Burmester option on the S-class adds a speaker pod on the roof for rear passengers. The drivers are pointed at an angle so the sound is 'correct' for rear occupants.



Porsche Panamera has separates in the rear door, with the mid/high mounted high up near the B-pillar.



You can probably consider these mounting locations as a starting point for your project.

Some separates have tweeter pods that can be stuck on top of the rear window sill that shouldn't require drilling.