Recording interest payable

Assuming the car is owned (titled to) the company

create a fixed asset account called car

create a sub fixed asset account called car - accum depreciation

create a long term loan liability account named for the loan

enter the down payment and use the car fixed asset account as the expense (reason) for the payment

then a journal entry, debit car fixed asset and credit loan liability for the total amount of the loan

when you make a payment use the loan liability account as the expense (reason) for the payment

when next months statement comes in it will show the amount of the previous payment that was interest, do a journal entry, debit interest expense and credit the loan liability for the amount back dated to the previous date of payment, then make the next payment.  Rinse and repeat each month

If the car is a personal car all the above does not apply, though you can use business funds to make the payments.  enter the payment and use owner equity drawing as the expense (reason) for the payment