new speakers in the fox?

Hello first of all I am new driver’s license and not long on the road with my fox, I only noticed that there are no speakers in the back. therefore I wanted to ask if I can install these boxes “Hifonics ZXi62 16 cm 180 Watt coaxial system” and if they are sufficient? I want to have a good sound already. I hope you can help me many thanks already in advance=)