Jay Leno is saying "Good bye".

It took a radio disc jockey to remind Jay Leno where he'll stand in "Tonight Show" history when he walks off the stage for the last time Friday. Leno was at the wheel of one of his famous vintage cars when he heard the DJ conduct a pop quiz: Who's the second-longest-running host of "Tonight," after Johnny Carson? "The guy on the radio actually got it before I did," Leno said Thursday, smiling. "It just sort of made me laugh. I went, 'Oh, that's pretty good.'" Maybe even better than good? "I come from 'pretty good,'" replied Leno, unfailingly modest in interviews. "If somebody wants to say even better, that's great." He will have posted an impressive 17 years as "Tonight" host, but well short of Carson's three decades that ended with his retirement in May 1992. Leno debuted as "Tonight" host a few days later. He leaves the show atop the late-night ratings, his run abbreviated by NBC's decision five years ago to create a succession plan that gives "Tonight" to Conan O'Brien. Billy Crystal put together a great good bye!! Click here to see the video!