In the mid 80s in Pakistan, an idea started that Compressed Natural Gas (CNG) could be used in gasoline engines by doing minor tuning to existing and new gasoline automobiles. The Hydrocarbon Development Institute of Pakistan provided funding to further the cause. Today Pakistan is one of the leading countries that has a plethora of Japanese automotive being built in Pakistan with dual fuel options (petrol and CNG) for retail sales.
What truly and literally started as shade-tree mechanic experiments now is an alternate fuel solution for tens of millions of automobile owners in Pakistan.
Click here for an example Suzuki.
Click here for the large number of dual fuel setup kits that can be purchased and installed in a gasoline car.