What should I look for in a used Nissan Micra hatchback?
Micras have become a byword for reliability, and rate well in the What Car? Reliability Index.
In fact, most problems arise from poor maintenance rather than something going wrong on the car. Chief among these is timing chain wear, which usually happens because past owners have left it too long between changing the engine oil. A rattle from the top of the engine at idle signals big bills for a replacement chain tensioner, while misfires are often caused by condensation at the spark plugs.
Corroded brake discs are common, but replacements are cheap and simple to fit, and the pads should be renewed at the same time. Suspension knocks, too aren't too much of a worry. They're often the result of worn bushes, which are cheap and quick to fix.
More serious is rust in the front chassis cross member, which will eventually result in your car failing its MoT test. Replacement is possible, but expensive.