1) If I’m saving money to pay for my car insurance, do I have to pay Khums on that?

2) If I give Khums on that amount then I won’t have enough money left to pay for my driving insurance.

1) Yes, If the date of Khums has come
2) If the payment is to be paid immediately, then you can take it. I mean if you want to pay insurance within few days after khums date then you can take away that amount before calculate khums