Why modify a perfectly good car?
Road and weather conditions can vary by countries and seasons, what fits one market or one customer might not be the best combination for another.
Generally larger tires increase off-road capabilities for most conditions, especially in snow. In Iceland people have been experimenting with using bigger tires in snow for over 25 years. People used to use snow chains on the tires to increase the traction and to pull you further through the snow. Soon people discovered that by lowering the air pressure to 2-5 psi, large tires could make a normal 4wd vehicle drive on top of a soft snow.
Early on modifications were mainly focused on off-road capabilities. The customers were mainly off-road enthusiastic individuals, utility companies and farmers. As demand increased from people who wanted to try something new or just liked the look of a bigger car and the possibilities the big car offered, the focus was more and more placed on maintaining drivability under normal conditions and maintaining high reliability. Soon owning a modified vehicle became a lifestyle for many people; the possibility of travelling in the highlands and getting to places very few had ever seen became attractive to many people, even though most of the time the vehicle was used for on-road driving. Style and image has therefore become one of the key issues when designing modifications.