I'm familiar with Little Feat's "Willin'" mostly through the cover Linda Ronstadt did way back in the 1970s. Something called it to mind the other day and these days it's super easy to find old video, or chords and lyrics. I knew the basic idea of the song but hadn't really inspected the lyrics, and on inspection they're really something. The prosody ("the patters of rhythm and sound used in poetry") is occasionally quite striking and I bet that's a big part of the song's memorability.
Some of it is fairly obvious, like the alliteration in the first couple of lines of the chorus:
"I've been from Tucson to Tucumcari, Tehachapi to Tonopah"
and a couple of lines later:
"Driven the back roads so I wouldn't get weighed
And if you give me weed, whites, and wine ..."
All those w's. ;-) But maybe a little less obvious, and to my mind more impressive, is the quick string of x/ks and hard-c sounds in these lines (you can even consider that they're set off by the g's amidst them) AND the repetition of the O vowels:
"Now I've smuggled some smOKeS and fOlKS from MeXiCO
BaKed by the sun every time I gO to MeXiCO"
There's a lot happening there. One result is that it feels very singable. The words are pulling you through. Meanwhile the words also tell a story; it's not all that easy to achieve a good balance of sounding good and making sense. It's one reason so many memorable songs have 'catchy' nonsense lyrics: they're easier to make memorable.
The other thing, prosody aside, is the the composition is yet more proof that basic chord changes will get you a LONG way if you put interesting melodies and harmonies on them. People used to laugh about "three-chord punk songs" but this song has ... four chords. It's basically in G and it uses the major I-IV-V chords and the relative E minor. That's IT.
Stephin Merritt of The Magnetic Fields is similarly basic in a lot of his great songs.