I’ve purchased a car with 0% interest, is the amount left on the car loan deductable form my wealth when calculating Zakat.

Alhamdu Lillah

The only deductible debt from the Zakatable wealth is the due debt only. So, in your case for example, the monthly car payment is deductible, but not the whole debt.

The above rule is applied  to any other debt or financial obligation; house payment, utility bills, tuition fees, taxes,..etc are examples for the legitimate deduction from your Zakatable wealth or pool of money that is subject to Zakah.