"An international survey by Yahoo! Autos reveals that, among residents in seven different countries, Americans and Chinese talk to their vehicles the most (69% and 57%, respectively), while Italians are the least likely to hold a conversation with their cars (29%). Italians are least likely to flirt (while driving, anyway) - just 18% - compared with Americans (62%) and Germans (41%). Silver is the most popular color in France, Spain, and Italy, while the UK and Germany opted for blue. Americans picked black as their top choice.."

At the risk of making a sweeping generalization, I would hazard a guess that Italian drivers don't speak to their vehicles precisely because they're too busy yelling obscenities at the other drivers.