If you didn't think Keith Olbermann could get any more insufferable, then you didn't watch his appearance on the Late Show with David Letterman last night. While he admitted, "I screwed up. I screwed up really big on this," and "It’s my fault that it didn’t succeed in the sense that I didn’t think the whole thing through," he discussed his $10 million/year salary (part of a $50 million/5-year contract he wants Current TV to commit to), "I didn’t say, ‘You know, if you buy a $10 million chandelier, you should have a house to put it in.' Just walking around with a $10 million chandelier isn’t going to do anybody a lot of good."

Olbermann quit/was dismissed from Current last week, after joining the upstart but struggling upstart network last summer after his MSNBC flameout. Even though he was being paid millions, he didn't think his show or the network were up to snuff from the beginning. On the Late Show, Olbermann also complained how his car service didn't show up one day because Current hadn't paid the invoice. For $10 million, we're sure he could have afforded a cab! But the Post (of course) has the dirt on Olbermann's car service habit:

Liberal bloviator Keith Olbermann spent his last days at Current TV driving colleagues nuts with rants about “smelly’’ drivers who had the audacity to talk to him, according to startling e-mails obtained by The Post.

“The problem is with him . . . the man who professes to be for the 99% doesn’t want any of the 99% talking to him or being near him,” an accounting executive complained in one of the missives.

An assistant, who had just about maxed out her corporate card in a desperate attempt to find a car service whose drivers would meet Olbermann’s exacting standards, e-mailed Accounting:

“I bet you wish I was joking about this . . . but we have yet another car service we need to open an account with.

“Any chance we can get this ASAP? I keep putting the charges on my corporate card and I’m afraid it will go over the limit soon!”

Olbermann said he felt bad for his staffers, "They put their careers at risk for me and I didn’t get a chance to say good-bye to them or thank them for the work they did with me and I’m… you know, I’m so proud of them because the show editorially was never better but I let them down because it didn’t continue."

Olbermann also said he hired the lawyer that represented Conan O'Brien in his parting with NBC.