'https://gist.githubusercontent.com/eunicetu16/887aeb4a2f1cb34cc8c9890a2767f1a8/raw/779e47af52b9f30adbeb3abafc5b063a643ed545/highway_mpg.csv'

The original dataset is from 'https://corgis-edu.github.io/corgis/csv/cars/', and take only 'Identification.Make' and 'Fuel Information.Highway mpg'. Clean the dataset to have only 7 cars made that are needed.