Living in China where they dont know what a sound system is

Hi I have been living in China for nearly four years now and have recently bought my first car here. Its a 7 seater van with lots of space in the back. I have recently managed to find a Sony head unit for it. I went to an Audio specialist and they offered me some proper cheap stuff. Didnt know if the advise they were giving me was correct. I have joined this site hoping to find out some info and get some help in turning my van into a quality sound system.