OK, all you Angela Lansburies.....
It wasn't a rental car, nor a hire car, it was a courtesy car - their car was in the garage for repair.
The two in the car are married to each other. So, spousal privilege, neither partner can be compelled to testify against the other partner, except in cases of domestic abuse or violence against a minor or sexual offenses against a minor. (But a partner can be compelled to testify FOR the partner - by the partner.)
And, because of the above, the two can't be charged with perverting the course of justice.
So, there you are.
And somewhat ironically because all this common law nonsense is the logical result of coverture. It was only about 150 years ago the first laws in both England
and the US began to allow a married woman to maintain some *limited* rights over her own property, but only after "protecting" the husband's property from suits involving his wife's property and contracts. The other big change was where the husband had exclusive rights over their children, now women were "liberated" to have equal control over their children, which, de facto, still left the husband in control over the children. Children's rights would wait quite a few more decades....
-mr. bill