I think it's because there are so many people in the U.S. they feel they have to make some noise to be noticed. Be that personalised cars, bling jewellery or whatever. Over here a standard Maserati is a stand out statement in its own right. I have 1 of only 3 GranSports in my city. Those that do highly modify their cars to personal taste find the market in a smaller country is very, very limited so the price falls.
Also the first policeman to see those extended wheels here would ban the car from use, until the registration authorities had gone over it from top to bottom. You have no idea how picky they were when I brought a UK import into my state from another state.