This Song Is Sung by Ricky Gervais on "The Office" series one, episode 4.
Check it out, its well worth a listen
Most versions of this song are corect apart from Ricky uses his plectrum to 
pluck the treble E string, and uses alternative directions of strumming the chords

        C       F       Am    G
E-------0-0-0---1-1-1---0-0---3-3-3--------------------------------------- 
B-------1-1-1---1-1-1---1-1---0-0-0--------------------------------------- 
G-------0-0-0---2-2-2---2-2---0-0-0--------------------------------------- 
D-------2-2-2---3-3-3---2-2---0-0-0--------------------------------------- 
A-------3-3-3---0-0-0---0-0---2-2-2---------------------------------------
E-------0-0-0-0-0-0-0-0-----0-3-3-3---------------------------------------

Intro 

C F Am G  x2
C          F         Am          G  
Pretty girl on the hood of a cadillac yeah
C          F         Am      G
She's broken down on freeway 9
C       F             Am        G   
take a look at her engine starter and..
C          F            Am         G
leave her purring and i roll on by, bye-bye.....

Listen to the song to get the rest of the words and speed of strumming etc.
hope you like it, it sound pretty much exact to the way he plays it on tv.
post any comments on it so i can see how you like it