"The car chosen for this study is an urban electric hatchback car, designed for Indian conditions." "Length(mm) 3280....."
The dimensions given match a Mahindra e2o:
https://autocatalogarchive.com/wp-co...2o-2016-IN.pdf
Their best rear spoiler lowered the drag by 5.6%. They say it extended the range by 3.5km, but don't give a base range. The range in the brochure (above link) is listed as 120km, so a 2.9% improvement. They did not say what drive cycle that would be though, nor does the brochure. Brochure does say it has a top speed of 81 kph though, so not fast.
(Their airdam did nothing at best, and hurt in some configurations.)