An inexperienced clerk wrongfully entered the managers salary into the insurance account. The double entry would be?

If the cost of servicing a company's car was debited to a non current account assets account instead of being debited to the motor expenses account?

First you need to reverse the original entry then your correct entry will be:
Debit Motor Expense and Credit Cash for the amount paid.

Or you can Debit Motor Expense and Credit the Asset that was originally debited for the amount paid.