CNG smell in Cabin, , bro that is hazardous and can cause fire or blast, empty the cylinder completely and close the cylinder and dont use it, or light a fire near to it, secondly coils is a popular issue with suzuki cars on CNG ,that is why i am strictly against CNG especially on Suzuki efi cars.
A suggestion is to get the coils fixed and remove CNG, as u hardly get CNG anyway and even if u do the pressure aint good which results in knocking and bad performance and destroys the engine.
First on your list should be the CNG issue, make the car engine and performance wise perfect and then move on to suspension, after that go for cosmetic