Robin Williams did Elmer Fudd doing the Pointer Sisters.  It starts
out something like "I was dwiving in my cah, I tuhned the wadio on". 
Where can I hear that?

Hi lahad and thanks for the question.

The song is called 'Fire' and the lyrics are:

"I'm driving in my car
I turn on the radio
I'm pulling you close
You just say no
You say you don't like it
But girl I know you're a liar
'Cause when we kiss Fire"
http://gilliver.net/music/bruce/lyrics/live.html

....and you can hear the Robin Williams/Elmer Fudd version at the link
below.
The file is the first one on the page and the file name is
"fuddfire.wav"
http://www.defnet.com/~claytor/sounds.htm   (and yes itīs funny!)

Thank you for the question, and if you need any clarification of my
answer do not hesitate to ask.

Regards

THX1138

Search strategy:
"robin williams" "Elmer Fudd" 
://www.google.com/search?hl=pt&ie=ISO-8859-1&as_qdr=all&q=+%22robin+williams%22+%22Elmer+Fudd+%22+&btnG=Pesquisa+Google&lr=

Just what I had in mind.