Chords used:

open G5 :                       G5

Special D5 with no high F#5 : D* 

e--0-- | 
B--3-- | 
G--2-- | 
D--0-- | 
A--0-- | 
E--2-- | 

open C5 :                       C5

C5 :                         C5

e--2-- | 
B--3-- | 
G--2-- | 
D--0-- | 
A--0-- | 
E--2-- | 

open E5 :                      E5

open A5 :                      A5

At the chorus Mark plays a little riff off of an open C chord with a 
changing base note:

e----------------------------- | 
B----------------------------- | 
G------0------0------0------0- | 
D----2------0------2------0--- | 
A--3------2------0------2----- | 
E----------------------------- | 

G5      D5 *     C5
You are a car
G5      D5 *     C5
You are a hospital
G5              D5 *
I'd walk to hell and back
D5
To see you smile

C chorus riff
On saturday

G5      D5 *   C5
You are a star
G5      D5 *           C5
You are a sea of air
G5               D5 *   
I play great keyboards
D5
Of horses' teeth

C chorus riff
On saturday
On saturday

G5       D5 *                  C5
            I'd like to tell you
         E5        D5                 A5
How I feel
                   D5
I'll probably keep it
           C chorus riff
'til saturday
Oh saturday, saturday
Oh saturday, saturday
Oh saturday, saturday
Oh saturday, saturday
Oh saturday, saturday