What are the key areas to check when buying a used car?

[MilesAnn]

When purchasing a used car, it is necessary to check the vehicle's documents, including the motor vehicle registration certificate, motor vehicle license, and purchase tax payment certificate; check whether the vehicle has been involved in any accidents, as used cars carry certain risks; and inspect the vehicle's condition for issues such as oil leaks and aging parts. Checking the vehicle's documents: Whether the used car's documents are complete directly affects whether the transaction and transfer can proceed. Therefore, the first step is to verify if the vehicle's documents are complete. A used car should have the following documents: motor vehicle registration certificate, motor vehicle license, and purchase tax payment certificate. Checking if the vehicle has been in an accident: When inspecting the vehicle itself, the first thing to check is whether it has been in an accident. The best way to determine if a car is an accident vehicle is to examine the weld points, especially those on the front radiator frame and chassis beams, under the door seals, on the rear trunk panel, and on both sides of the chassis. A car produced in a factory is welded by robots, so the weld points will be uniform. In contrast, an accident vehicle is manually welded by a body repair technician, resulting in uneven and irregular weld points. Checking the vehicle's condition: A car can generally be divided into four major components: the engine, body, chassis, and electrical system. Modern engines are highly computerized, and any faults will trigger error codes. Therefore, the first step is to connect a diagnostic tool to check for error codes and data streams. Common minor issues include engine oil leaks and aging rubber hoses.

[StColin]

What I fear most when buying a used car is encountering a car that has been in an accident or flooded. Focus on checking whether the welding points on the longitudinal beams in the engine compartment are neat and original, and look for signs of tampering on the door hinge screws. Pull the seatbelt all the way out to check for water stains or mold. Feel the corners of the spare tire well in the trunk for rust. Start the car and listen for any metallic knocking sounds from the engine, and test the gearshift for any jerking. During a road test, turn off the music to listen for any abnormal noises from the chassis, and find a slope to test the handbrake's effectiveness. Don't trust the seller if they say it's just minor scratches—use a paint thickness gauge on repainted areas, and the truth will come out. It's advisable to spend 500 yuan to bring an experienced mechanic to inspect the car, which can help you avoid major pitfalls.

[AuroraMarie]

When inspecting a used car, focus on these three critical areas. The body frame is most crucial—check underneath the car for any folds or welds on the chassis beams, and peel back door seals to inspect if the weld points are even. For the engine, start it cold to listen for unusual noises, pull out the dipstick to smell for burnt odors, and check the amount of black carbon on the exhaust pipe. Don’t overlook the electrical systems either—test all buttons repeatedly, and open/close windows and sunroof ten times to check for smooth operation. If the tire production date is much later than the car’s manufacturing date, the odometer might have been tampered with. Checking insurance records is the most reliable way to verify past major accidents, as policy amounts spike after significant incidents. Finally, confirm that the VIN and engine number match the vehicle registration document.

[SanRyan]

As someone who often helps friends inspect cars, I have a quick checklist. First, park the car in a well-lit area and check the body lines at a 45-degree angle—repaired panels will show distorted reflections. Second, press along all the rubber seals; replaced seals feel harder. Third, use your phone to record the undercarriage and check for oil leaks around the engine oil pan or transmission. After starting the engine, rev it to 3,000 RPM—if the exhaust smells sweet, it indicates coolant burning. When negotiating the price, check the tire tread depth; if the tread patterns don’t match across all four tires, aim to cut at least 2,000 off the price.

[SanMakayla]

Afraid of being ripped off when buying a used car? Here are clever tricks to spot flood-damaged vehicles. Feel deep inside the seat rails for sand or mud—rusted cigarette lighter rings are a dead giveaway. Sniff the AC vents; a musty smell mixed with disinfectant is a classic sign. Pull out the steering wheel adjustment rod to check for rust on the metal shaft. Pay special attention to the fuse box—white oxidation marks here are a sure sign of water damage. Fully extend the seatbelt; yellowing and stiffness at the base are clear indicators. Don’t forget to lift the floor mats and feel the back of the carpet—even sun-dried flood cars remain damp here. Dealers often overlook these details; spotting them can help you negotiate a 30% price cut.

[MacPenelope]

Experience from inspecting 300 used cars: Check the paperwork first, then the car. Be wary if the green book shows more than three ownership transfers, and avoid cars with liens. Insurance records are more reliable than 4S shop records—claims over 10,000 RMB are suspicious. Focus on major issues during inspection: Transmission oil that’s black and smelly means at least an 8,000 RMB discount; scratched engine cylinder head bolts indicate major repairs; caked mud on wheel arch liners suggests off-road use. Pro tip: Use a magnet on the body’s waistline—if it doesn’t stick, the area has been filled with putty. Finally, check brake disc groove depth—worn-out discs mean budgeting for replacements.