When looking to buy used cars like the 2020 Volkswagen Tiguan L PHEV 430PHEV, the absence of maintenance records requires buyers to prioritize thorough inspections. Key areas to check include the lithium - ion battery’s health (critical for PHEV performance), which can be assessed via professional diagnostic tools to verify remaining capacity (typical PHEV batteries retain 80 - 90% capacity after 50,000 km if well - maintained). Additionally, inspecting the hybrid system’s components (e.g., motor, transmission) and engine condition through third - party or authorized Volkswagen service centers is recommended. For PHEVs, standard maintenance intervals (e.g., battery checks every 10,000 - 15,000 km) should be confirmed to ensure long - term reliability.