How is zakat paid on the amount of a car that has been sold and whose rent is paid monthly?

Zakat is not obligatory on the value of taxi cars themselves. Rather, it is obligatory on their income if it reaches the nisab (threshold) and a hawl (full lunar year) passes over it. If the car is leased, then Zakat is related to the rental income. However, if the car is sold for investment, there is no harm in the sale if it is done with the owner's permission. It is not permissible to guarantee a fixed monthly amount in an investment; instead, profits should be divided based on agreed-upon percentages. In this case, Zakat becomes obligatory on the price of the car after a hawl has passed.