It would be unfair to give a verdict on this vehicle because the Maruti Cervo has not been launched yet. We would suggest you wait for the official announcement.
In general, the down payment remains in between 20-30% of the on-road price of the vehicle and ROI varies between 9.25-11.5% and it totally depends on the CIBIL/Credit score of an individual. So, we'd suggest you walk into the nearest dealership to know the final finance quotation and documentation as they will be the better person to assist you. You can click on the following link to see the details of the nearest dealership and selecting your city accordingly - Car Showrooms.
