I say test drive them all. At the speeds that your dad drives, you will lose fuel economy in any car. The one thing that stands out for the Prius C is the potential to get great gas mileage at a relatively cheap price. I don't think you can go wrong with a Mini, Fit, Yaris, Civic, Corolla, Golf or any other compact cars that can achieve 40 mpg on the highway. GL! If you have any questions about the Prius C, let me know.
2011 E92 l SSII l Fox Red l ZP2 l ZCW l ZCV l 19" l 6MT l DDC l EPS
2012 Toyota Prius C(my new daily).
2002 Nissan Pathfinder - 301.6K and Junked.
2000 Mitsubishi Montero Sport - Rolled & Totalled.
1995 Cadillac Fleetwood - RIP.