CNG Cars

Hey Folks! This is a post for the people who are automobile engineers in Maruti Suzuki/Tata/Hyundai/Toyota and have know-how of CNG Leak test and CNG filling process. I'm an automobile engineer working in an OEM and I am currently evaluating the manufacturing feasibility of factory-fitted CNG variant.
I'm looking to connect with engineers working (or who have worked) at Maruti Suzuki, Tata Motors, Hyundai, Toyota, or any other OEM who have knowledge of the CNG Leak Test and CNG Filling processes on the production line. I have some doubts and need some guidance.