For those who it might interest, it appears that quote isn't even in the movie. After some research on the net last time, it seemed that it was in Shrek 2, which I put into my DVD player as a background for my regular activities of the night. I never heard the line.

I searched an online transcript of the movie and it didn't return any result.

So I'm pretty sure, as I thought before stumbling upon this quote referred to as coming from the movie, that this line was only used in the Ford commercials following the release of Shrek 2.

Oh well.