From wikipedia:
This was the highest charting hit and greatest claim to fame for the now all-but-forgotten early rock group The Playmates. Despite this, they had four other Top-40 hits in the Billboard Hot 100 in the late '50s / early '60s. The Playmates were Chic Hetti (piano), Donny Conn (drums), and backing vocals (and presumably auto hornist) Morey Carr.
The Playmates all hailed from Waterbury, Connecticut, and met at the University of Connecticut, where they originally started touring Canada as a comedy group called "The Nitwits." They gradually transformed into The Playmates as they took up singing, though they always kept a comedy routine in-between songs in their stage act.
Now for the car lore: This song (from 1958 - before most of you were born) is also known as "Little Nash Rambler" or simply "Nash Rambler" and is sometimes mislabeled or even requested by that name on the Dr. Demento show. A Nash Rambler was a kind of car produced by Nash Motors in 1950, and it was a bubble-shaped little bug that was to become the first compact car manufactured and sold in America. As you can imagine, the car met with some scorn from the majority of the American driving public, who were used to driving big Caddy land yachts and looked down their noses at compacts, when they noticed them at all. It was World War 2 that introduced Americans to compact cars, when servicemen stationed in Europe got to like them over there. The humor of this song revolves around the ironic race between a Cadillac and a Rambler, with a stunner punchline.
The lyrics:
[Very slowly]
Beep beep beep beep
His horn went beep beep beep
While riding in my Cadillac
What to my surprise
A little Nash Rambler was following me
About one third my size
The guy musta wanted to pass me up
As he kept on tooting his horn
I'll show him that a Cadillac is not a car to scorn
Beep beep beep beep
His horn went beep beep beep
[Slowly]
I pushed my foot down to the floor
To give the guy the shake
But the little Nash Rambler stayed right behind
He still had on his brake
He musta thought his car had more guts
As he kept on tooting his horn (beep beep)
I'll show him that a Cadillac is not a car to scorn
Beep beep beep beep
His horn went beep beep beep
[Normal speed]
My car went into passing gear
And we took off with gust (whoosh)
Soon we were going ninety
Musta left him in the dust
When I peeked in the mirror of my car
I couldn't believe my eyes
The little Nash Rambler was right behind
You'd think that guy could fly
Beep beep beep beep
His horn went beep beep beep
[Quickly]
Now we were doing a hundred and ten
This certainly was a race
For a Rambler to pass a Caddy
Would be a big disgrace
The guy musta wanted to pass me up
As he kept on tooting his horn (beep beep)
I'll show him that a Cadillac is not a car to scorn
Beep beep beep beep
His horn went beep beep beep
[Very quickly]
Now we're going a hundred twenty
As fast as I can go
The Rambler pulled along side of me
As if we were going slow
The fella rolled down his window
And yelled for me to hear
"Hey buddy how do I get this car outa second gear?"
Written by: Donald Claps, Carl Cicchetti
The little Nash Rambler pic:
The song, from 1958:
https://www.youtube.com/watch?v=eDSk4zwjg5A
not heard of that before 
