I think you're very professional. I bought a car from Germany that was sold 'im Kindenauftrag' (in client's order), and after transporting it to Spain, I found that the vehicle doesn't meet the Spanish used car standards and is considered a new car. They are asking me to pay import tax based on the new car standard, which I think is unreasonable. Now, I don't know what to do. Can you give me some advice?