bro madman, IMHO, if those ppl who put in rear speakers just for ur rear passengers, i think they dunno much bout ICE or maybe he haven heard the correct setup car.

if ur system is correct, u dun need rear speaker for rear passenger to listen to music.

Those boom boom boom that u mentioned, cause they r spl kaki's thats why u only hear boom boom boom.

In SQ, we want our sub to play low frequencies, instruments like tuba, double bass, drums n etc...

U can try to compare a 2 or 3 way coaxial n a compent set, u will definately find out that coaxial higher frequencies much more higher than component sets.

Some icer also running rear speakers too, most of them using the same component as at front component. When u sit on the front seats, u cant hear the rear speakers sounds.

Why dun those who wanna invest on rear speaker, to put all the rear speakers amount of money into the front, so that u can njoy much better qualities of music.

my 2cts nia