China has a large number of luxury cars and a fast turnover rate. For luxury cars of the same year and mileage, the FOB offshore price in the Chinese market usually still has a 10%-15% arbitrage opportunity after deducting shipping costs, especially for models with high depreciation rates.

4S dealership records are directly connected to the manufacturer's database, making the data hard to tamper with and the most reliable, with original parts guaranteed; third-party repair shops usually are not connected, making their data unverifiable. Therefore, we only consider the connected records from 4S dealerships as valid historical documentation.

Most models adjust through the central control screen menu, while a few models (like some BYD or MG) retain physical levers or paddles on the center console or steering wheel. We will check if the drag feel when the system engages is linearly normal.