When young people hear "giddy up 409," the first thing they might think of is the household cleaner. Formula 409 has used the song as a commercial jingle, and for many, that might be the only time they've heard the song.
Yet "409" was actually recorded in 1962 by the famous pop group, the Beach Boys. They weren't shills for the household cleaning product - the song was actually a tribute to the Chevrolet 409. This wasn't a specific model, but an engine offered by the automaker in the early 60s, especially in models like the Corvette.
The 409 gets its name from the 409-cubic-inches of displacement in the engine. The 6.7-liter V8 was one of the most powerful engines back in the day, and was extremely popular with hot rod enthusiasts - as well as harmonic pop groups.
Most of the lyrics in "409" err on the side of simplicity, with lines like "she's real fine, my 409," as well as the bass-heavy "giddy up 409." Of course, there were also a few nods to the more technical aspects of the car, such as the line "my four-speed dual quad posi-traction 409."