Donald Trump got his medical deferment because he suffers from “Intrarectal Cranial Inversion” Jay Leno joked this morning at TCA.

Leno came to TCA to talk about debuting his Jay Leno’s Garage on CNBC, debuting October 7 at 10 PM.

But, one reporter asked Leno if he had any Trump jokes, noting new CBS Late Show host Stephen Colbert had, days earlier, told TCA he was desperate to debut on CBS, calling his online cracks about the GOP frontrunner just so much “dry-Trumping.”

Leno obliged with his own Trump gags, noting that Trump had called into question Sen. John McCain’s heroism because he did not realize that without McCain the north would have lost the Civil War, from which Leno segued into the Trump medical condition gag.

“His head is up his ass,” Leno add, explaining the joke, apparently sensing that words of too many syllables did not play in the room.

Leno also forecast the GOP race would be winnowed down to Jeb Bush vs Trump, aka “The Tortoise and the Bad Hair.”

Colbert will do well with his new, bigger CBS platform, Leno forecast. “People think he’s a raging liberal. He teaches Sunday school. I think he’s a pretty conservative guy. I think he will do well with middle America,” said Leno, who played very well with middle America during his run on NBC’s Tonight Show.

Asked if he had been asked to be a guest on Late Show with Stephen Colbert, Leno said no, but, “I’m kind of loyal to NBC.  On the other hand, he noted, he was James Corden’s first guest when Corden took over CBS’s Late Late Show. “He’s a nice guy, I like him,” Leno said of Corden.

“NBC has been trying to kill me for years,” Leno said of one episode of Jay Leno’s Garage in which he sits in the back seat of an Audi that drives itself, while it sped at 110 MPH around a racetrack.

“I’ve been with NBC my while career…I really like being here, I like being part of a family, a continuing history,” Leno said of moving over to CNBC. “I’ve still got my first car I bought in Los Angeles. I’m still on my first wife. I like progress – it’s change I don’t like.”

All those years he was hosting Tonight Show “I really wasn’t that interested in celebrities,” Leno confessed. Particularly irksome were publicists who insisted their celebrity clients were geniuses. “I met more geniuses when I was at Tonight Show,” he snarked.

Leno talked at length about some of his car purchases over the years, including, most recently, a Tesla. Most passionately he talked about the ’51 Hudson he bought from a 96-year-old lady, though he already owned one, after learning she’d bought the car new and, since her husband died in ’96, had dusted the car regularly but not driven it. “I had to buy it,” Leno said. He restored it and invited her to go for a ride in the car, with her two children who were by then in their 70’s. “She had such a wonderful time — the time of her life,” Leno said of that trip, noting the previous owner recently died, at age 101. “It was so much fun to fix it up and take her for a ride. That’s a case where you really buy the story more than you buy the car.”

In October of ’14, CNBC confirmed Leno would be returning to The Networks Of NBCU, to will host a “new” primetime series for the network — tentatively titled Jay Leno’s Garage. In one of those incredible coincidences, that also is the name of his Emmy winning web series. Jay Leno’s Garage is a hit with more than 1 million subscribers on YouTube and more than 105 million lifetime views.

Putting the CNBC spin on it, the network said the show would be “the place where Jay shares his passion for all things automotive, including best investments, valuations and the inner workings of the car collector’s market.” Probably more accurately, Leno said, “This show will be about anything that rolls, explodes and makes noise.”

Leno, the all-suffering-est NBCUniversal loyalist, is being deployed to help boost the media conglom’s cable business network.

CNBC already tested the idea of a Leno-hosted primetime show when it telecast Jay Leno’s Garage: The Ultimate Car Week over  the last Labor Day weekend. At 10 PM that Sunday, Leno clocked 416,000 viewers (139,000 of them in the news demo), more than tripling the crowd CNBC clocked in the same time slot during Labor Day weekend in 2013. That special/backdoor pilot was an extension of sorts to Leno’s popular web series still found on NBC.com — eight months after NBC gave Jay the boot, for a second time, from his Tonight Show gig, this time to make way for Jimmy Fallon.