When evaluating a Willys Mini Jeep, focus on the engine displacement (typically 110cc, 125cc, or 150cc) and the cooling system (air-cooled vs. oil-cooled). Ensure the chassis is made of reinforced tubular steel with a powder-coated finish to prevent rust. For transmission, verify if it is semi-automatic (3 forward, 1 reverse) or fully automatic, as this impacts the end-user experience. Additionally, check the maximum load capacity, which should ideally be at least 150kg to 200kg for two passengers.