Cars & taxes

I have my car registered and insured set to my parents address, for cheaper tax reasons. I have all of my other documents; work, bank, license, health insurance, ext addressed to my current home. When tax times comes i will have to prove I lived with my wife and stepson for the year in order for us to claim our step son. Should I be worried I won’t be able to claim him if my car information is set to a different address?