I would suggest you Passo 2005/06 Model. Reasons:
New Shape. Much better than Vitz 1999/02 Model.
Latest and Fresh Interior. Vitz 1999/02 Model has pretty old fashioned look with awkward position of ODO meter. Which they changed in 2nd gen.
Better Engine. Latest Technology which gives better mileage with good response.
Cabin of Passo is quiet as respect to 1st gen Vitz which has noisy cabin.