Designers will tell you that all the safety regulations mean cars will now look very similar. Jaguar said as much when their new car happened to look exactly like any newish Aston Martin you care to mention. The Tiida could well be on the Micra platform, that would explains why it looks a lot like the new Clio.
I've always thought the new Astra looks one hell of a lot like a MK2 Clio from the front, I spotted a bright blue VXR coming at me from quite a distance not long ago and it looked just like an Arctic Blue 182.