Since you're into space saving and family oriented car.

Get a CD player with at least 2 RCA preout ideal will be Pioneer 3050UB.

Front install component set and rear install 6x9 speaker, 2 set of RCA cable connect to a 4 channel amp.

There is one seller selling Sony 4 channel amp 60w x4 for RM 380. Good enough to power up your sound system.