Playing Downloaded Playlists in Car Head Unit

[halibut17]

Plan

Free/Premium

Country

Device

(iPhone 8, Samsung Galaxy 9, Macbook Pro late 2016)

Operating System

(iOS 10, Android Oreo, Windows 10,etc.)

My Question or Issue

Spotify (Premium) on my desktop PC running Windows 10 and in my car's head unit that has Android Oreo. Location is Australia.

I listen to Spotify downloaded music while driving in offline mode, as I have very limited mobile data. Whenever there is a Spotify suggested playlist I like I usually sit in my driveway (connected to my home WiFi) and download the playlist before I drive away.

However, my WiFi is not the fastest and the download process takes quite some time. More often than not I give up and just drive off listening to the radio.

Is there anyway of downloading the desired playlist on my PC which has a cabled connection, and somehow making it available to play offline in my car?