What is the legitimacy of a company obliging its employees to insure cars purchased with an interest-free loan from it, with the insurance value being paid in installments over four years?

It is permissible for a company to lend money to its employees to purchase cars, and then to mortgage the cars until the loan is repaid. However, if the company leaves the car in the employee's possession, the mortgage becomes void. Commercial insurance on cars during the loan period is Islamically forbidden.