SO, reading all these reviews I was very skeptical and unsure about this purchase but went ahead with in anyways because to me it was the best money could buy at this price point. Boss Audio is an American company too, which helped ease my mind. Anyways it came packaged up as any brand new product. All wiring is labeled so you know what is what BUT it will not tell you what the wires are for your specific vehicle, that's up to you to find out. Also, you must know how to install these units. I feel that so many negative reviews are from people that are not educated in vehicle electronics and wiring. The newer your vehicle the harder it probably will be to install and The less experience you have, the harder it will be to install. Do your homework, know what your doing, test it BEFORE putting it all away into the dash.
One review on here stated that on Chevy trucks the screen will interfere with the shift lever in the Park position. This is true on my 2001 Suburban, but it is nobodies fault and what I would call an undesirable characteristic. The screen stops itself if anything interferes with its operation. I try and stay aware and make sure it's closed before exiting the vehicle. It opens just fine, just gets caught up on the lever in the PARK position when the screen is folding in to close.
All in all, this is a great little unit that packs a lot of features and sounds amazing. My suburban had aftermarket audio and video installed when it was new. With aftermarket amps that controlled everything. With this I was able to hook up the amps for the speakers and subs with the RCA cable hook ups. So it worked out perfectly in my situation.
I also hooked up two existing DVD headrests to this unit, it works flawlessly and great because I can control and see what's going on while I'm driving. Although I don't think you should be watching TV while driving, I had to hook it up this way so I could run the rear screens while driving. Then I just close my screen and let the kids watch. Ive seen enough of Daniel Tiger the way it is.

CHECK UPDATE BELOW:

Original review:
Bluetooth audio playback, works well. Nothing out of ordinary. Connecting is pretty easy searches right when you start car given you know how to connect.

Update 6/12/2017:
I'm decreasing this to one star. The unit no longer works. It seems as if the copper contacts are no longer touching. When putting pressure on the left side where the metal contacts are it turns on and works as long as I'm holding it down. DO NOT BUY THIS!!!! YOU'LL REGRET THIS!!

Ok...mixed reviews here, so I'll break it into PRO's and CON's.

PRO:
Sleek design.
Large (large enough) screen to see everything you looking for.
All wires were labeled which made wiring super easy.
Total install was less than 30 minutes.

I have a couple CON's, but really only one that matters, however, I'll list them all.

CON:
There is a lag when going from station to station. Not a huge deal, but super annoying when you're channel surfing.

If you have any device over 4GB I am convinced it will not load via the USB port. I have put just about every USB compatible device in the port and it never loads.

The sound quality sucks...make that SUCKS! The radio is fine, however, when you switch over to Bluetooth streaming it always forgets your presets, and the sound volume is about half it's normal volume. I have to turn it to 39 (the highest volume) to get the same quality of sound when it's at about 17 on the radio.
But it doesn't stop there. The AUX port is even quieter that that. The sound is so quiet (even at 39) that you can't really hear the music. Maybe that's good for safety purposes, but it's not a good sound and it's not very good for blasting your playlists on your way to work.

I'm giving it two stars because it's a simple radio with simple features and it was easy to install, and it was better than the broken factory I had before. However, if I were "upgrading", I'd be really ticked off and I'd be asking for a return.

So far this has been a great unit for my truck and easy wiring install too. I had to use my old aftermarket wiring harness to plug into the factory harness, I still have to finish the wiring to parking brake so I can watch DVD's, other than that I'm very pleased and happy with Boss product.

I'm reviewing this for what it is, a $50 receiver. Simply put, it doesn't get much better than this for under 50 bucks. Installation was easy so anyone comfortable enough with a screwdriver, wire stripper, electrical tape or heat shrink (I like to be neat so I used heat shrink) should be able to install this.

The good:
For 50 bucks, you get Bluetooth connectivity, SD card, USB, and AUX inputs, decent power output (enough to drive your typical 4 speaker stereo system) and neat looks. Bluetooth pairing was a breeze and I was instantly streaming my music files or streaming services. Loaded up an SD card and I now have music for weeks. The USB port is useful if you have an old iPod full of music, but it doesn't charge your device. Bluetooth streaming is very clear. Hands free talking is not bad. Overall you do get a whole lot for such low price.

The bad:
SD card file navigation is a pain. Just don't do it while driving, ever. Just set it to random and be happy with that. It also doesn't seem to recognize AAC (iTunes) files, only MP3 and possibly WMA. Bluetooth calling works great, for you as a listener, but for the other end, you might have to speak a bit louder than usual. I was told I sounded fairly clear but distant at freeway speeds. The buttons do feel cheap, in fact the volume button got stuck a few times in the depressed position (it brings up the bass/treble/fader menu when you press it) a few times at the beginning but not anymore. I think it might eventually break. Also the remote control is a bit hard to read and lacks textured "dots" to help you navigate through it without looking. Overall navigation is a bit confusing but I guess once you get used to it, then it's not too bad.

In the end, this is a budget head unit and it does offer a whole lot for the price, so issues should be expected. If you want a real quality head unit then I don't need to tell you that a $50 unit won't be it. But if you want to update your 90's cassette player or CD player with a 21st century Bluetooth and portable media expansion port unit on a budget, then this is it.