The lyrics were based on blues musician Robert Johnson's 1936 "Teraplane Blues." Robert Plant used car parts as metaphors for sex - "pump your gas," "rev all night," etc.
When played live the band would sometimes segue into their song "Gallows Pole". This song was used to showcase Jones' skills as a keyboard player, and it consequently features a long instrumental section which Jones used for solos.
One of Plant's favorite Zeppelin songs, this became a concert favorite and was frequently played on the radio when it came out. He sang it on his 1988 "Now and Zen" tour, and also at his daughter Carmen's 21st birthday party in 1989 with Jason Bonham on drums.
Jawn- Trampled Under Foot
Sami- That song makes me hot in the pants
Jawn- I love you sami.