Experience turbo lag and power surge during road tests; check for significant oil accumulation at the turbo intake and intercooler connections (slight oil vapor is normal); and use OBD to read the real-time boost pressure peak to see if it meets factory settings.

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.

We cannot open each tire to inspect the inside. However, if a visual inspection reveals severe creases on the tire sidewall, it indicates that the run-flat tire has been driven for a long time at zero pressure, damaging its internal structure. We would recommend replacing it before shipping.