Don Lemon is not saying never about returning to CNN -- which fired him last year -- and even has some requirements in mind, but he's also very realistic about why it ain't happening ... most likely. The famed newsman joined us on the "TMZ Podcast" this week, and revealed he'd be open to going back to his former employer if they offered a particular company car -- one more associated with Elon Musk, ironically. We're confident he was joking, but Don was serious about not holding his breath for a call from CNN. He says there's no bad blood between them, but also explained why it's probably not a great fit, for him at least. ICYMI ... Don did get back on CNN briefly last week to discuss the fallout from his Elon interview -- and he admits it felt surreal to be talking to the outlet that cut him loose. That feeling might explain why he's not all gung-ho about any potential for a reunion, but the other reason he's hesitant ... the hours! Don told us, "I don't know if I would want to do a show 5 days a week or what have you. It would just depend on what it is." As for a possible return to X -- where Elon pulled the plug on Don's new show after their sit down -- the journalist tells us that's also unlikely, and he called the whole experience a waste of his time. Now, while DL sounds all kumbaya with CNN, the same can't be said about Elon. When we raised that professional break-up, he slammed the billionaire for failing to live up to the promises he made after first inviting Don to launch a show on the social media platform. Yet, despite his strong feelings on the matter, Don says he still tries to have a never-say-never stance regarding X. As they say, never burn a bridge!