Is purchasing a commodity in installments at its current price, through an interest-based financial institution, considered a stratagem to legitimize usury?

It is permissible for an institution to sell a car by installment at its current price or with an increase, because the debt constitutes a share of the price. Purchasing a car through the bank is permissible if the bank pays the installments without an increase, and this is considered a goodly loan (qard hasan). However, if the bank pays the installments and then takes more than it paid, this is an interest-based loan (riba), and the introduction of a commodity into it is a trick to legitimize usury. There is no objection if the bank is merely a guarantor and the individual pays the installments himself.