Image on iphone and in car

Ok, so i am new here, am pretty good with tech stuff and mp3tag seems fairly easy to use, BUT.......

Having set covers for some of my tracks, I am using one in particular to test.
Here is my sequence:

  1. Added a music directory

  2. selected a track

  3. Right click and added a cover image

  4. Added artist tags etc etc

  5. saved using the save icon

  6. Opened itunes

  7. add file from library and synced my iphone

Heres the problem.......
No tags or image appears on my iphone or in car infotainment system

WHY??

Where am i going wrong or what process have i missed out???

I thought this was going to be easy!!!

Thanks in advance

As far as I see from the screenshot: there are a lot of flac files that do not have any tag data.
Then there are a fair number of wav files - and AFAIK iTunes does not support tags in wav files. It is probably the same in your car.

Thanks.

Forget the flac files and all the other files, I am just testing on the one file called She, as highlighted in the image.

Firstly, I don't know what you mean by AFAIK?? I am very very new to all this, so I have no idea what that stands for or how it impacts on what I am trying to do. Are you saying that I can't use wav files to add to my library?? in actual fact, its the only file that will go onto my phone, flac files can't be synced by itunes, and only wav files can..... so i am trying to work with a wav file to simply have the cover version of my own tracks that i create appearing on my iphone and in my car rather than a blank appearing which is just nasty.
Can this be done or not?

AFAIK = as far as I know (see perhaps this external page:
50 Popular Texting Abbreviations & Internet Acronyms — Explained)

That is what learned about iTunes.
see also here:

and here: