We open on a black cab drivng along the London streets.
One of the passenger doors is hanging off, the back window is smashed and the upholstery is ripped to shreds.
Cut into the dtiver.
CABBIE: I had that Susan Boyle in the back of my cab the other day...
The passenger door falls off altogether.
Lovely and brief.
Good one Lazzard. As a different slant maybe:
CABBIE: I had that Susan Boyle in the back of my cab the other day.... I'm not surprised she's single.
Actually, stick with yours 
Last night I thought of having the cabbies face all covered with felt pen - possibly with the word 'cheese' written on his forehead.
I don't know why.
Just made me giigle.