Which Queen song was the B-side to 'Bohemian Rhapsody' on its original 1975 single?

Which Queen song was the B-side to “Bohemian Rhapsody” on its original 1975 single? “I’m in Love with My Car” was the B-side. Written and sung by drummer Roger Taylor, the hard-rocking track appeared on the same 1975 album, A Night at the Opera.

The single was released in the UK on 31 October 1975, with “Bohemian Rhapsody” on the A-side. Taylor’s song was inspired by a roadie’s devotion to his Triumph TR4, and its engine-revving ending used the sound of Taylor’s own Alfa Romeo. Taylor reportedly pushed strongly for the song to be included as the single’s B-side.

Listeners sometimes confuse the B-side with another Queen single or album track, especially “’39” or “You’re My Best Friend,” both of which are also associated with A Night at the Opera. The pairing also had financial consequences: because both tracks were on the single, Taylor received publishing royalties comparable to Freddie Mercury’s royalties for the A-side.