It is not advisable to rent a car in Istanbul as traffic is horrendous, the parking places are scarce. Use the public transport and taxis. It is up to you but if you are planning to go outside of Istanbul with your family for example Bursa, Sapanca ( 2 or 3 hours drive ) etc. it would be better idea to rent a car instead of taking bus from Istanbul.
It is not advisable to rent a car in Istanbul as traffic is horrendous, the parking places are scarce. Use the public transport and taxis. It is up to you but if you are planning to go outside of Istanbul with your family for example Bursa, Sapanca ( 2 or 3 hours drive ) etc. it would be better idea to rent a car instead of taking bus from Istanbul.