If you're after an automatic with economy of 45-50mpg then you'll need to consider a diesel engine. Unfortunately small-engined diesel automatic cars with cruise control are quite rare. You might want to consider a BMW 3 Series compact (the three-door hatchback version). We've seen a 320td SE models with around 70,000 miles for £5995, which are diesel and have cruise control. Others to look at include the Mercedes-Benz C-Class. If you're after something newer, we've seen a few Vauxhall Vectra 1.9 CDTi models with both an automatic gearbox and cruise control.