I think you can argue THX had a cult film status. At least two music videos have been inspired by it. Queen did one in the 80’s and a Hip Hop duo did their own homage in the 90’s.
Here’s the Queen video. Funny enough even though I was aware of George Lucas even at a young age, I think I saw this video before I was even familiar with THX-1138.
I didn’t even know the song.