Customization
In the USA and Australia in particular, owner drivers, and even fleet operators, go to great lengths to customise their vehicle in a similar fashion to a custom car. This involves fitting larger exhaust systems (often highly polished stainless steel or chrome plating), extra lights and custom paint, among other things. Such tractor units attract lots of attention, and can be beneficial for promoting their businesses; such tractors can be matched with customised trailers. Some companies have one custom truck, or at least one tractor unit that is different, or more powerful, than the rest, to act as their flagship.
Read more about this topic: Tractor Unit