Inspecting a pre-warmed car
A cold start is a one-time diagnostic event per visit: startup rattles, smoke on first fire and cold-idle behaviour reveal wear that disappears within a minute of running. Sellers who warm the car before you arrive erase that evidence, deliberately or not. Ask for the car cold, and in summer add a hot-restart test after a ten-minute heat soak.
Skipping the AC stress test in winter
Between November and March, feeble air conditioning still feels adequate, and the most expensive common fault on UAE used cars sails through unnoticed. Insist on measured vent temperatures at idle over five minutes, not a hand over the vent. A system that only cools at speed has a fan or compressor problem waiting for June.
Reading a cleared fault memory as a clean car
An empty fault list with incomplete readiness monitors means the memory was wiped recently, which is the opposite of reassuring. Insist on a re-scan after 50-100 km of driving, or make the deal conditional on it. The absence of history is a finding, not a pass.