The Wagon R is a nice car, very good headroom. My head hits the roof on almost all the cars I have sat in (including the Santro !) at the backseat.
The Wagon R is however a strict city car. On the highway, its shortcomings are barred. Its boxy design means fast cornering is a hair raising experience and it skids if you push it. In the city, acceleration is very peppy, but going flat out on a nice long stretch of highway, it will take its time to reach a fast speed. It goes out of breath after 100 kmph.