Is it permissible to take a loan from an Islamic bank to buy a car with the intention of buying something else?

It appears the questioner is referring to "Tawarruq," which is when a client purchases a commodity from a bank, not desiring the commodity itself, but rather wishing to obtain cash. Tawarruq is permissible if the bank purchases the commodity first and then sells it to the client. In this case, the client is allowed to keep the commodity or sell it and use its price to purchase whatever they desire.