What can I do with the USB?

2017 Prius Two does not have Android Auto. Just Bluetooth. You can plug in a USB stick with audio files and play them. Your manual gives you more details.

 

If you are just trying to use it as a USB stick, allowing the car's audio system to access the music files, have you adjusted the phone's USB setting to allow file transfer? For security reasons this should default to power-only on the USB port, and require some user intervention on the screen to allow any data modes.

(Beware, I am no expert here. I plug only a real USB stick of music files into my car. Never my Android.)

 

We have a 2015 Prius V level 2 so we have the basic sound system. We loaded music onto a USB memory stick. Make sure that you format the stick as Fat 32 before loading your music or it won't work. You will see an index of your albums on the touchscreen. You can select what album/song you want to listen to and choose random to jump around on an album or jump around on all the albums. We see the artist,m album title and song title on the touchscreen display while the song is playing..

 

But the 2016 Gen 4 likely had a different radio than your Prius v based on Gen 3. The USB stick requirements may or may not be the same.
The OP is free to search online for their owners manual if they did not receive one with their car.

 

The 2017 manuals are here.

 

I just got the new RAV4H and there is no CD player and not even an AUX port.

So I have been loading CD's onto USB and that works fine.
I can also load movies or videos..works fine...I have not been doing much ripping for 10-yrs now getting back into it.

As far as missing AUX port, you have to buy a $25 bluetooth transmitter and then you can input from CD walkman into the Bluetooth.

We do have Apple CarPlay but we can't drive anywhere anyways so I have been learning the USB.

 

The Gen 4 has an Aux port, right beside the USB port. At least my 2017 has one.

 

As stated, we have a 2015 Prius V level 2. I checked our manual and it didn't specify a maximum USB capacity that it would permit but here are some of the file types and file structure limitations from our operators manual. Yours may be the same or similar.

USB memory
●Compatible devices USB memory device that can be used for MP3, WMA and AAC playback.
●Compatible device formats The following device format can be used:
• USB communication format: USB2.0 HS (480Mbps) and FS (12 Mbps)
• File system format: FAT16/32 (Windows)
• Correspondence class: Mass storage class MP3, WMA and AAC files written to a device with any format other than those listed above may not play correctly, and their file names and folder names may not be displayed correctly. Items related to standards and limitations are as follows:
• Maximum directory hierarchy: 8 levels
• Maximum number of folders in a device: 3000 (including the root)
• Maximum number of files in a device: 9999
• Maximum number of files per folder: 255

I copied all of our music (6 gb) onto the USB stick. Each artist/group has a folder. Within each artist/group folder are the albums and within the albums are the individual songs so we are using 3 levels. This is probably pretty typical of the music folder on a windows computer.
You can select random from the artist/group level and songs from anywhere on the USB will play. You can select random at the album level and play random songs from just that album.

 

If you read the manual I linked to you would have seen that applies to your car too.Too lazy to pull over and put in another stick of music??



I'll let you read the 3 pages of details yourself.

 

The other thing I also tried was using the same USB stick I made for RAV4 (with MP4 movies) in all of my 3 HDTV's, which range in age and brand.

So the 4 devices have some differences in Play-Back compatibility (which you can read in the respective manuals). The universal sound mode seems to be MP3. some accept AAC sound but not AC3 sound and vice versa. So if you are ripping your own videos or music videos to get the soundtrack, you can use something like Handbrake video software and select the sound format your specific device accepts.