Girl buying a used car

Ok, so I would like to buy a car to replace my little Daewoo, as much as I love the little Matiz it's probably time for a change now the car is 8 years old. Thinking of going for a used car from a local dealer. I've been trawling the web and it looks like Lifestyle Europe have a lot of dealerships so a fair amount of choice. So far, have seen a great value used Ford Streetka...yes I'm still banging that old 'I want a convertible' drum! Along the more sensible lines, I'm also considering a 2006 reg used Ford Fiesta, a 2005 reg used Ford Focus, a silver used Renault Clio, a 2006 reg used Ford Fusion and a very cute 2007 reg bright red used Ford Ka - then my nails definitely would match my car!