James Corden and Barbra Streisand. Picture: Screengrab/YouTube

Barbra Streisand had never sung "out loud' in a car before doing 'Carpool Karaoke' with James Corden.

The 'Woman in Love' hitmaker is the latest star set to jump in the British comedian's Range Rover for a sing-a-long of her greatest hits on his 'The Late Late Show' segment, and she surprised her fans with the confession.

Confirming the episode, which will air on Thursday on CBS in the US, the 76-year-old star tweeted: "They say there's a first time for everything... can you believe this was my first time singing out loud in a car? Had so much fun with @jkcorden - tune in to @latelateshow Thursday night! #BarbraWalls (sic)"

In a teaser clip, the 'A Star Is Born' star tells Corden: 

"I don't usually put the radio on to hear music so do you really have to hear music?", as they duetted on 'Don't Rain on My Parade', the 1964 soundtrack to classic movie 'Funny Girl'.

The actress-and-singer follows in the footsteps of the likes of Lady Gaga, Sir Paul McCartney and Michael Buble in taking part in 'Carpool'.

A day after her 'Carpool' episode airs, Barbra release her first album in two years, 'Walls', which is inspired by Donald Trump and the current political climate.

The iconic performer admitted the 2016 presidential election "gave her energy" and the desire to express her views on her first record since 2016's 'Encore: Movie Partners Sing Broadway'.

She said: "These times gave me energy. 

"I felt so passionate about it. And music gave me that creative way to express my feelings. 

"I'm very grateful to have music in my life, to be able to do that."

Barbra has said that she doesn't care if people are turned off from buying the record because it's influenced by Trump.

She told The New York Times newspaper: "Truth has always worked for me, so to see the truth defiled every day is very, very painful for me. I only can do what I can do. I probably will turn a lot of people off.

"I can only be true to me as an artist and if people like it that's great, and if they don't, they don't have to buy it or listen to it. But me in real life is more important than me as the artist. As a citizen, that's the role."