Which is better, Suolang's MP3 car or Xianhe's MP3 car?

In terms of sales volume, Solang's car is the first on the Internet. Personally, I think the quality is ok. I sold a lot. No one has ever reflected the problems such as poor quality and loud noise you mentioned. Is the noise improperly adjusted? Is the quality of the downloaded songs good and the speakers in the car poor? These all affect the quality.