Piazza Del Campo was originally going to be karting track in Gran Turismo 5. It was removed due to copyright reasons.
It was shown that Piazza Del Campo was supposed to be the "Main Course" on the Gran Turismo Karting Experience in the Special Events.
This track was only shown twice. Once at Gamescom 2010, and again on the Gran Turismo website in a video titled "GT5 Karting Trailer". The video was quickly pulled as soon as Polyphony was threatened with the lawsuit.
The only cars seen driving on this track were the Fiat 500F, the Fiat 500 Abarth '08 and the Gran Turismo PDI RACING KART 100.