Same title in America (hooray!); but a stupid story imo.
"IMDb storyline :-
An American realtor living in England is dissatisfied with what he believes to be his humdrum life. One weekend while his wife is out of town, he gives a ride to a woman he sees stranded on the road. One thing leads to another, and he soon finds himself enmeshed in a plot involving a diamond robbery, gangsters and murder."
OK, he was seemingly stuck in a dead end job with a token wife, but any sane person wouldn't have let it get out of hand as he did, for e.g. just handing over his car keys to a young women in a weird sense of duty so she could help sort out her supposed "brother" who was in some sort of bother.
I actually muttered "Why doesn't he give her the deeds to his house as well" Nah, too far-fetched.
Lead actor Arthur Kennedy I vaguely recognised, and did these English ones in uncredited parts :-
Michael Balfour, Kenneth Cope (again), and the ubiquitous Sam Kydd (of course!)