Is an employee's acquisition of a car from the company, whereby the company pays its monthly installments to the bank, and then ownership is immediately transferred to the employee, with the employee bearing the remaining installments should he leave employment, considered an usurious transaction?

The issue is summarized as the company guaranteeing you to the bank to obtain a car loan, which is to be repaid to the bank in installments deducted from your salary.

If the bank will give you the value of the car in installments without interest on the principal of the loan, and without stipulating late fees or forbidden usurious conditions, then this is permissible and there is no harm in it, because it falls under the category of a good loan (Qard Hasan).

However, it is common for banks not to lend except with interest, and this is forbidden. Also, if the creditor stipulates a punitive financial penalty on the debtor for late payment, then it is a void and forbidden condition because it is the usury of Jahiliyyah (pre-Islamic era).

It is not permissible for the company to take a fee from you for issuing the guarantee letter, because a guarantee for a fee is not permissible.