Bhai if u have bought an abused car and it troubled u certainly doesn't mean its a bad car.
i have got three of my friends who have bought santros of different models and everyone has kept these vehicles for more than 5 year and still one of them own it till now.
Everyone of them enjoyed it and say one of the best cars in this category. u just need the right mechanic simple.
Buying a santro in todays time is not advisable because an unmolested or properly maintained santros is very hard to find and yet the parts finding will be not easy.