Starring Rupert Grint, Julie Walters, and Laura Linney. Rated PG. Opens Friday, November 3, at the Fifth Avenue Cinemas

Driving Lessons is the latest addition to a long line of British films in which viewers are invited to applaud rebellions that would likely frighten them in real life. But what else are movies for anyway?

In this case, the central rebel is ?almost-18 Ben Marshall, a painfully shy vicar’s son played wonderfully by Rupert Grint, known from the Harry Potter series. The lad can’t quite connect with his father (Nicholas Farrell), a gentle preacher who would rather be birding, and he can’t quite escape his mother (Laura Linney), a manipulative shrew who uses Jesus as a club to beat him into submission.

Mom also uses the frequent sessions of the title as a mask for assignations with a handsome young man who, handily enough, is to play the Nazarene in an upcoming pageant. The fact that this sleek hypocrite is played by Linney, with an upper-crust accent and the fixed glow of the soon-to-be-beatified, gives this outright villain a kick we wouldn’t otherwise enjoy.

Ben is actually going to learn to drive, thanks to a summer job he takes: tending to a sailor-mouthed actor called Dame Evie Walton. That she is played by Julie Walters is cause for extreme delight. First we are amused, and then Ben is charmed—if only after being shanghaied, first on an impromptu camping trip and then to pilot her ancient Citroí«n all the way to Edinburgh, where the Dame is due to read poetry and he is due to become the luckiest boy in Scotland.

Of course, he doesn’t initially know he’s going to meet a comely lass called Bryony (Michelle Duncan), so he’s busy getting hung up on a ringleted good girl (Keeping Mum’s Tamsin Egerton) who finds him “weird” because he writes thoughtful poetry. And he’s unaware that Evie is better known for a bad ’80s soap than anything she did on-stage. But all that will come while pulling away from mommy’s Bible strings.

The semi-autobiographical script from director Jeremy Brock, who also wrote the colour-coded historical dramas Mrs. Brown and Charlotte Gray, isn’t shy about presenting a war between two maternal figures, one toxic and one life-affirming. And there’s no doubt which he favours, even if Evie shamelessly exploits the boy for her own ends. She doesn’t hesitate to play the cancer card, for example, when Ben balks at the next adventure. “These tits are time bombs,” she explains, sweetly.

The movie is just as manipulative, straining for frankly preposterous Big Moments toward the end. But almost all of them pay off, in both drama and laughs, and you forgive it for taking you out of your way.