i wud personally believe that amongst all the cars u mentioned, Santro has the best drive as its engine is excellent with gud road grip. however, Alto is 1000 cc but has the same engine as that of Potohar with upgraded gearbox. its not to gud on power-to-weight ratio thingy, and somehow is extremely sluggish specially with AC on. Cuore on the other hand is a 850cc car, carby engine, but excellent power. however, it lacks on interior room and economy as it is not too lite on CNG OR petrol...so, if i were u, i wud go for a Santro. if not, then a Cuore. Alto is not a choice