The Foo Fighters have a confession to make.
The rock band made their debut on James Corden's "Carpool Karaoke" last month, belting out their greatest hits like "Best of You," "Learn to Fly" and "All My Life."
As fun as the segment looked, the bandmates admitted that the actual filming wasn't that joyous.
"By hour three in dude’s car, it got less fun,” guitarist Pat Smear told NMEin an interview released on Friday. "It kinda went on. When we stopped at Guitar Center, that felt like we were done, but it was like, 'This is halfway.'"
WATCH: Foo Fighters Have a 'Full Circle' Moment With James Corden on 'Carpool Karaoke'
Frontman Dave Grohl said that shooting the segment was "a little uncomfortable." While he didn't doubt that Corden was a music fanatic, the Foo Fighters frontman wasn't too keen on singing his own songs in that setting.
"Oh he definitely is [a music lover], and he's a very nice guy,” Grohl expressed. "But, y'know, I don’t mind singing my own songs at Glastonbury or the O2, but if I had to sing you a song right now, I’d be too embarrassed."
The bandmates also agreed that they wouldn't have minded "singing other people's songs," with Grohl noting, "I could do that all day."
"We did The Ramones and Rick Astley, but they didn’t use it," the singer-drummer revealed. "I don’t know why."
WATCH: Foo Fighters Give Epic 3-and-a-Half Hour Surprise Concert in Chicago
While the Foo Fighters didn't have the time of their lives, fans enjoyed watching the segment. Their "Carpool Karaoke" video already has more than 6.5 million views and counting.
ET caught up with the Late Late Show host backstage at the Creative Arts Emmys last month, where he teased more "fun" special guests.
Hear who's on his list in the video below.