“Trading Paint” is a laid-back ode to the transformative gravitas of a letting a beard go grey and the competitive pleasures of Big Time NASCAR’s “small time” — Super Late Model dirt track racing.

There’s not much to it, and frankly, that’s a problem. We need more “movie” here — more emphasis on conflict, more generational stresses, more obstacles to romance.

It’s about a racing son trying to break free of his daddy’s cut-rate team and then having to race the old man in the dirt, as the track announcers say, “like a true Southern soap opera.”

But when those same announcers enthuse, “Hell, you can’t WRITE this any better!” we know better. Yes. Yes you can.

Still, it’s a solid un-embarrassing B-movie vehicle for John Travolta, who lets himself take on a drawl and some age even as he clings to that fake hairline like grim death itself.

He plays “Sam the Man” Munroe, a legend of local dirt track racing in and around Talladega, Alabama. The area might be famous for being home to a NASCAR “superspeedway,” but next door Eastaboga has a dirt track also home to “Talladega Nights,” and Sam made his name there, and where he’s passed on his passion to son Cam (Toby Sebastian of “Game of Thrones”).

But Cam is tired of going out, risking his neck, “trading paint” (colliding, or at least rubbing fenders) with the field, always losing to Bob Linsky (Michael Madsen) in the end because Dad’s motor lets him down.

“What’choo wan’ me t’do?” he drawl-complains to his baby mama (Rosabell Laurenti Sellers, also of “Game of Thrones”). “Be a loser all mah life?”

So when Linsky purrs in his ear sweet nothings about wanting to help, being his friend and all, Cam listens.

Daddy blows his fuse, but hell, there’s a new schoolteacher from “Up North” who’s moved in next door. She’s played by Shania Twain and widower Sam? He feels “Like a Woman” right about now.

The budding couple spill their “stories” at a lakeside picnic — she’s divorced, his wife died in a car accident which Sam doesn’t say was his fault. But he’s haunted by it as if it was.

She wants to know about his “hobby.”

“Racin’ ain’t no hobby.”

There’s just a hint of the colorful blue collar world captured in last year’s terrific stock car racing documentary, “The Last Race,” about the only track left in that hotbed of NASCAR glory, Long Island, New York.

“Hobby” or not, this sport is eating up all Sam’s cash. The deal he has to make to score a new car (with a veteran of TV’s “Gunsmoke” bargaining with him) is small-time and folksy, like most everybody here.

Kevin Dunn is the obligatory limping mechanic named “Stumpy,” and makes a cornpone character feel lived-in.

“Who put the buzz-kill bee in YOUR bonnet?”

The equally obligatory trip to a favorite waterin’ hole where some jerk figures he’s up for a little needlin’ Sam over his racing failures and has-been status begins, unfolds and ends exactly the way you figure it would.

There’s nice detail to Sam’s life — a garage that looks as if it’s used as a garage, the old wood frame house with a wraparound porch and a vast collection of racing trophies and memorabilia that he lives in, the ’70 Boss Mustang that he keeps tucked under a car cover (The collectible car that his wife died in, maybe?).

But what I mean by “Trading Paint” requiring “more movie” is in the father-son relationship, where the kid might blame Dad for mom’s death, or be bitter about being “held back” by the old man’s crummy race cars.

The movie doesn’t get into that.

You spent the money getting the great Michael Madsen as your heavy. Give his “history” with Sam more baggage, more hurt, more edge.

And the love story? Fuggedaboutit. The delicate way Travolta hugs Twain as if he’s afraid of catching the Lyme Disease she contracted years ago and leaves heat, sexual or romantic attraction out of it.

Love Travolta, but that’s never been his strong suit on screen.

He’s long been one of my favorite actors, always been the most pleasant movie star to interview. But as JT settles into this C-movie phase of his career, with titles like “Gotti,” “Speed Kills” and “I Am Wrath” barely warranting release, a fan just hopes for a picture that doesn’t embarrass him.

“Trading Paint” accomplishes that. But the director, screenwriters and production leave too much in the garage and not enough on the track, to borrow an analogy. There was a better movie in this story, this setting and this cast.

MPAA Rating: R for language

Cast: John Travolta, Shania Twain, Toby Sebastian, Barry Corbin, Kevin Dunn, Rosabell Laurenti Sellers

Credits:Directed by Karzan Kader, script by Gary Gerani, Craig R. Welch. A Saban Films release.

Running time: 1:29