Hiting the radar：It simply means that people began to notice it and talk about it and buy it. "Radar" here is a figurative way to refer to public awareness.

E.G. Fake cures and tests seem to be flooding social media these days and thus it will be interesting to see how many hit the radar of the authorities.

Cooking with gas：to be making very good progress or doing something very well. 

E.G. With the updated software, I was really cooking with gas. I got the project done in half the time.