It seems as though Miranda Lambert's budding friendship with NASCAR phenomenon Danica Patrick extends past their fictional criminal partnership in the singer's latest video, 'Fastest Girl in Town.' NASCAR's 'Queen of the Road' made a surprise appearance at Lambert's concert Monday night (Aug. 20), stunning the Rock the Rapids crowd in Grand Rapids, Michigan.

The famed driver joined Lambert and her Pistol Annies band mates onstage for a cover of Roger Miller's classic 'King of the Road,' but the lyrics were appropriately altered to 'Queen of the Road' to better reflect Patrick's status as the first lady of NASCAR.

Patrick was reportedly "shy" while on stage, but seemed to revel in her friendship with country music's reigning ACM and CMA Female Vocalist of the Year. Though Patrick is not an outright country music fan, she was totally enamored by Lambert, referring to the singer as a “kindred spirit.”

“Miranda was great,” Patrick said of working with the country superstar. “I appreciated her asking me. Every time somebody famous knows who I am I always say, ‘I can’t believe you know my name.’ It’s a funny thought. Maybe I sound silly, but it’s still really cool when somebody famous like that knows who you are.’ She says, ‘Oh, yeah, I totally know who you are.’ She’s like, ‘For weeks now it’s me and my trainer, going to work out for Danica.’ How did she say it? The ‘Danica workout’ or something. I was very flattered. She was really sweet.”

Last night's show was the last domestic concert stop for Lambert before heading to Canada for a few dates. The singer is currently on the road for her headlining On Fire Tour co-promoting her latest solo studio album, 'Four the Record,' as well as Pistol Annies' 2011 release, 'Hell on Heels.'

Watch Miranda Lambert, Pistol Annies Sing 'King of the Road' With Danica Patrick