Air suspension is very delicate. If, after the vehicle has been stationary for about 12 hours, the height on one side of the vehicle drops more than 1.5 cm when measured from the wheel arch to the tire, we will determine that there is a slight air leak in the air spring or distribution valve on that side and warn you of the high subsequent repair costs.
Rust is a deal-breaker that photos can hide, so be systematic. High-risk areas to check: 1. Underbody and frame rails—surface rust is normal, but flaking or bubbling paint means advanced corrosion 2. Wheel arches and rocker panels—these trap mud and salt 3. Door bottoms and the trunk floor—water collects here; lift the trunk mat and look for dampness or repair welds 4. Around the windshield and sunroof drains—leaks cause hidden rust in the A-pillars Ask the inspector to do a magnet test: filler-repaired areas won't hold a magnet, indicating past accident repairs. A paint thickness gauge reveals resprayed sections—uniform readings around 80-150 microns are normal; spikes over 300 suggest bodywork. Cars from northern China (salted roads in winter) or coastal cities need extra scrutiny on the underbody. If structural members show corrosion, walk away—repairs rarely restore original strength.
Start with the owner's manual for your exact model and year—it lists the official service intervals and the required fluid specifications. If the manual is only in Chinese, ask the exporter for the English version, or check the manufacturer's website and owner community forums for your region. After the car arrives, do a baseline service even if the seller says it was just serviced: engine oil and filter, air filter, cabin filter, brake fluid check, coolant, and a 12V battery test. From then on, follow the "severe" or "extreme conditions" schedule rather than the normal one—dusty roads, short trips, and hot or very cold climates all count as severe duty, and intervals are usually shorter. Keep every invoice and record. A documented maintenance history makes warranty claims easier and protects resale value.
