This car radio amplifier from this schematic is a car audio amplifier based on the TDA7391 amplifier circuit which is a class AB audio power amplifier chip  specially designed for car radio applications.
TDA7391  car audio amplifier provides a maximum output power of 35 watts on a 4 ohms load impedance  , but  typically this circuit can provide around 26 W with THD 10% and 21 W with THD 1% .

If we use a lower impedance load (3.2 ohms ) the output power which can be obtained can be more than 26 W .

This car audio power amplifier require few external components and a 1.5 volts power supply ( power supply range accepted is between 8 an 18 volts) .
This car audio amplifier circuit diagram has many features like :  programmable turn ON/OFF delay , internal fixed gain , stand-by function , short circuit protection , overtemperature protection  and more .
The ST-BY function shuts down all the internal bias supplies when the ST-BY pin is low.
This audio IC is equipped with a diagnostic circuitry  which able to detect the clipping in the output signal (distortion = 10%).