Am looking to spend around £4k for a small, reliable, economic car (with low insurance) which will have to carry out a 50 mile a day round trip commute on dual carriageway & country roads.

Was looking for something low mileage so that at my mileage it will still last me a few years. A lot of 05-07 Nissan Micras were coming up in that price range; would you recommend and if not is there something else you would suggest instead?

Common alternatives showing up would be Fiat Puntos, Renault Clios, Vauxhall Corsas etc

Also in general, am I better going for an 07 reg with say 40,000 miles or an 05 reg with 20,000? What is more likely to play a more important role in determining the life and condition of the car - the age or the mileage?

If I go for a K12 micra, what common problems do I need to be aware of when viewing cars?