I bought the Boss BV9370NV because I wanted a cheap GPS that's "integrated" with the car that also played MP3s. The GPS on the unit worked fairly well and on a cold start it would take about 20 - 30 seconds to acquire the signal (which is not too bad).
But the unit has some serious flaws with regards to the radio, sound and build quality. About every 5 days, the radio would start scanning stations for no apparent reason and it would do this for any station you tune in to. Once this starts, there's no way to stop it so it's very frustrating when you're listening to a station. Also about 40% of the time the unit would boot up with no sound, you have to mute and unmute it to get the sound to work.
The quality of the build is fairly cheap, this unit developed a white vertical line on the screen (dead pixels) and I've only had this brand new unit for about 5 months. The customer service department is slow and non-responsive to my request for replacement.
So overall if you want something that works stay away from Boss and save your money for something better like a Pioneer.
I got the Boss camera hook up with this as well. Overall it has met expectations. The clock settings is the only complaint. The time zone settings are not accurate...also it appears the gps messes with the system time. I keep having to correct the date and time on occasions. Overall I'm very satisified. Like the ability to upload a custom wallpaper image.