Opinions as well as help wanted for USB

I recently purchased a Kenwood KMR-M315BT audio unit for my car. The cost was great.
I can send music to it via Bluetooth, Direct Aux in with a mini jack and via a USB port.
The USB port is the one I want to use the most. The specs. Kenwood wants for how it reads
mp3's and wma's are as follows:
Maximum number of folder layers 8
Maximum number of folders (per folder) 999
Maximum number of folders (per device) 999
Maximum number of files (per folder) 999
Maximum number of files (per device) 20480

The maximum number of characters for display:
File/Folder name 8 characters
MP3 ID3 Tag Ver. 1.x 30 characters

                    Ver. 2.x	64 characters<b></b>

I have about 50 artists and 150 albums to put on my USB drive.
My questions to you guys is:
What would you say would be the most logical way to
set up the folder tree so navigation is fairly easy and would you suggest a macro for that?

Thanks in advance.

What do you mean by "macro"?
Where is that "macro" supposed to run?

Sorry, not a macro but a format string.
Ex: [%artist% - %album% - $num(%track%,2) - %title%]

OK. As you like.
BUT: Scanning through a folder tree while you drive is fairly distracting. Just like texting and driving.
And: folder trees set up a fixed way to access the files.
So I would recommend to create a folder tree that features the most commonly used way to access the files.
E.g. if you group the files by GENRE, then create folders that are names like the genre.

You can easily create folder structures from the tags by using the backslash as separator between the file names and folder names, e.g.
%genre%\%artist% - %album% - $num(%track%,2) - %title%
(you can use it with the Convert>Tag-Filename function of a "Format value" action for _FILENAME)

If I'm driving, I have it set to "all random" (If I don't want to hear that song, I just have to press (>>)
For a particular album, I pull over for a moment.