It appears that the text is a product name or model: GMC C4500 Topkick. for GTA 5

GMC C4500 Topkick Utilly6 for GTA 5.
The GMC C4500 Topkick Utilimaster is a medium-duty truck that stands out with its large and powerful exterior appearance.
The vehicle has massive proportions, a square cab with a high roof, and wide steps for access.

The exterior design of the Topkick Utilimaster is filled with aggressive elements such as a massive grille, powerful bumpers, and large headlights. The vehicle is equipped with large wheels and wide side mirrors for driver convenience.