I do 36,000 miles a year commuting (95% motorway) and have been running a 2007 1.4 diesel Fiesta to keep fuel costs low. I've already had to replace the EGR valve and there are signs of further trouble with dirt clogging up - garages tell me this engine is renown for dirt and problems and I should budget for high maintenance costs as I put more miles on it; it has 76,000 miles on the clock.

I want to replace it for something with good fuel economy, say 55 mpg+ at motorway speeds, but not necessarily a diesel. Can you recommend a suitable small/medium car replacement? My key criteria are fuel economy and trouble free (low maintenance costs).