Yes, I would also try to make light of it. Try as best you can not to make others pick up the slack, such as you being too tired to ride your bike or too tired to take transit so you get rides from people. If you do get rides make sure you reciprocate in some form.
If you had never gotten a car in the first place the reaction would be less. It is a bigger deal to have a car then give it up.
You can always tell your family that you are giving up the car for the time being, and seeing how it goes. Then change the subject and ask them an unrelated question. People are generally more interested in themselves anyway.
