Install Location Help

Can you please help with the best locations for a 4 Head and STI-R install on a 2015 CLS? I was thinking two heads in front and two in the back, but i am open to suggestions. Any help would be greatly appreciated so i can guide the installer
I have attached a couple of pictures.
Thanks

Attachment 3914Attachment 3915

Front - ~6" spacing from the Left & Right edges of LP (under upper flat area of lower grill)
Rear - above & ~3" spacing from the Left & Right edges of LP