Utilize secured payment terms and consider a staged payment structure: 30% deposit, 40% after production/testing, and 30% after a third-party pre-shipment inspection. Demand a video walk-through of the vehicle's functions (screen lift, rotation, sound, and generator start) before final payment. For long-term reliability, negotiate a 1-2 year warranty on the LED modules and ensure the supplier provides a spare parts kit (sending extra modules, receiving cards, and power supplies) with the initial shipment.