If at Last You Don’t Succeed . . . : Television: The creators of the final episode of ‘It’s Garry Shandling’s Show’ were unhappy with it . . . so they wrote a new one.

Question: When is a TV series’ last episode not the last episode?

Answer: When “It’s Garry Shandling’s (Last) Show.”

Shandling has decided to call it quits after four years and 72 quirky episodes on the Showtime pay-cable channel, and, in the tradition of such sitcoms as “The Mary Tyler Moore Show,” “MASH” and “Family Ties,” he and co-creator Alan Zweibel scripted a grand finale that airs at 10:30 tonight.

In it, a character named Death kills the character named Garry Shandling. But at the funeral, Shandling rises up out of the coffin, telling his audience that he didn’t really die, only the TV character he’d played for these last four years had died. Then, all the regular characters stroll out for one last curtain call and one last quip.

But, it turns out, this isn’t the last show after all.

Shandling and Zweibel decided that as the denouement for a series that consistently tried to twist, mangle and break traditional TV formulas, the episode just seemed too much like all those other last shows. So they turned it into the third-to-last show by taping an epilogue in which the fictitious president of Shandling’s network walks on stage, chides him about such a “ridiculous” ending and then sentences him to two more shows.

The final, final episode--a parody of the Oscar-winning film, “Driving Miss Daisy,” featuring Dan Aykroyd as Garry’s brother Boolie and Paul Winfield as Garry’s driver Hoke--airs June 8.

“The last show didn’t come out as we thought it would,” explained Zweibel, one of the original writers on “Saturday Night Live.” “We probably ended up doing a little more of what we should have been making fun of. And we thought the ‘Driving Miss Garry’ episode was sweeter and felt like a more correct note to go out on. It incorporated more of our signatures. It had guest stars, we used the car, it was a parody of a movie. And we really liked the idea of Garry taking one last lap around the studio in the car and waving goodby.”

For Shandling, 40, articulating the reasons he decided to say goodby is even more difficult than coming up with an appropriately irreverent finale.

The series, which began as a video on Michael Nesmith’s “Television Parts” in which Shandling went on a date with Miss Maryland and narrated the hapless events of the evening into the camera, had been all-consuming, eventually taking Shandling away from his regular guest host spot on “The Tonight Show.” But it had given him an unfettered playground to indulge his and Zweibel’s wildest television fantasies.

The show had no rules. Shandling would talk to his studio audience or straight into the camera as often as he’d speak to the other characters on the set. He’d drive his car, actually a golf cart, around the sound stage. To indicate that a day had passed, technicians would simply turn the studio lights off and then on again.

In one typically absurd episode, Shandling went to “where the audience lives” to apologize for some bad jokes, climbing into the bleachers that held the studio audience. The area was decorated like a living room--complete with walls, pictures and lamps--and there he found the audience watching a different show on their television set. He begged them to forgive him and turn back to his show, and then, as a gesture of good will, he took the entire audience whale watching with pop star Sheena Easton.

“We did some really funny things on this show,” Shandling said. “Just some really odd things that you’d never see on any other show. We had a unique sensibility and a unique vision that I think we accomplished in about 12 episodes or so. We had done what we set out to do and to continue on for the sake of going on or for financial reasons, I just couldn’t see it anymore. I’ve never been someone who could find a groove and just mosey along. Once it’s been accomplished, I say, ‘Let’s move on.’ That’s sort of what’s ruined my dating life.”

Zweibel, who complains that he didn’t sleep in four years of churning out the series, said that he wanted to quit too because in a sense he had outgrown the show.

“Because it is such a personal show and Garry is the focal point, for me the time came where I wanted to say other things through other characters,” he explained. “I’m married, I have three kids and things were happening to me and I wanted new outlets for them. The show was so time-consuming that it was impossible to have your cake and eat it too. I mean, I have this play we’re reading in New York that I literally wrote at red lights while driving to and from the office.”

Nonetheless, both Zweibel and Shandling say they will miss it terribly. Shandling jokes that after a monthlong vacation in Hawaii, he’ll probably find himself sitting in his office on the Sunset-Gower lot until 3 a.m. every night out of habit.

But they are proud of the work they have done and satisfied with the limited audience the show was able to attract on Showtime and, for two years, on Fox Broadcasting. (Shandling has long said that because TWA showed the series on some of its flights, more people have seen the program while flying on airplanes than on TV. “The only demographic we know about our show is that 40% of our viewers are nonsmokers,” he jokes.)

With a little perspective a few years down the line, Shandling and Zweibel believe, their show will be to the situation comedy what “Saturday Night Live” has been to the variety show or what “Late Night With David Letterman” has been to the talk show.

“And I think that it will be rediscovered, in syndication or even five years from now,” Zweibel said. “I don’t think it will just go away and live on only in the minds of the 12 people that saw it. Maybe that sounds conceited or maybe I just don’t want to invalidate the last four years of my life, but I really think it’s going to find a niche.”

The 72 episodes will be resurrected on the Lifetime cable channel beginning either late this year or early in 1991.

As for Shandling’s future, Brad Grey, his manager and one of the show’s executive producers, said that Shandling has been asked to host three new talk shows--one for a network and two for syndication--is up for parts in several movies and is planning a stand-up comedy tour of the United States for later this year.

Shandling says he would love to get back into the talk show game, but he is worried about locking himself into such a job this soon. He and Zweibel have also written a film version of the series, “It’s Garry Shandling’s Movie,” but for now Shandling says he’d like to try playing someone other than Garry Shandling.

“Maybe Larry Shandling,” he jests. “You know, I really hate listing things that I’d like to do. I hate when I read those interviews where people say, ‘Oh and I’d also like to be president of the United States.’ And you just say, ‘Well, good luck.’ ”

Exhausted from shooting two shows in two nights, his back aching, Shandling, like a flustered college senior who has yet to decide on an academic major, apologizes for not having any specific career goals. “In three weeks, I’m sure I’ll be ready to take anything,” he says. But for a few minutes anyway, he’d like to enjoy life without an 80-hour work week.

And Shandling, who for many years got great comedic mileage out of his romantic misadventures, does have someone with whom to share his free time.

“Yes, I’m in a relationship now,” he gloats, “and my girlfriend turned to me yesterday at the wrap party and said, ‘But there will still be checks coming in, right?’ And I said, ‘Yeah right, honey--get used to it. We’re cutting back.’ ”