well it sort of means "swing", but specifically applied to driving.
the song is all about loss, mourning and cars.
"swang and swang and swang to the left/pop my trunk for fat pat's death..."
swangin' and bangin' (cf ESG's swang and bang as the track that really defined the term) refers to a very slow driving style where the driver makes the car weave lazy arcs down the road, left and right (swanging), while leaning at a ridiculous angle, almost into the passenger seat (cf. paul wall's "sittin' sidewayz"), and playing Screw tapes incredibly loudly (banging).
re things with a similar feel, they're not the same but i think you'd love any of the og ron c fuck action screwed r&b mixes. go to
www.mixtapetorrent.com and you'll find some.