There is no honest single lifespan for every vehicle graphic. Film type, print protection, color, sun exposure, road use, washing, fuel, abrasion, installation details, and the paint underneath all affect how long the work stays presentable.
The material is only one factor
A suitable film and protective finish matter, but the same material can perform differently on a shaded local van and a vehicle that works outdoors every day in heat, salt, and road debris.
Edges and high-wear areas need realistic expectations
Door edges, handles, fuel doors, rocker panels, utility bodies, and equipment surfaces receive more contact and contamination than broad flat panels. The layout should account for those conditions.
Care can protect the investment
Use appropriate washing methods, avoid directing pressure-washer nozzles at graphic edges, remove damaging contaminants promptly, and report lifting or damage before a small issue spreads.
Materials and production decisions depend on the actual surface, environment, size, expected life, and installation conditions. Send photos when you can.