Top Gear team answers the question by releasing a DVD regarding that issue. While the best car in the world cannot be chosen due to many different models for different tastes and purposes, Top Gear made the effort and selected The Worst Car in the History of the World.
The issue revolves around cars that are neither cheap nor low profile. Therefore, James May and Jeremy Clarkson decide to reveal them, all the way from Ferrari 458 Italia, Lincoln Continental Mark V to Lexus SC 430. How they do that can be seen in the promo video below: