HELP! He wants to use and expired car seat

JoMiFo • Married & Mom. 🎀8.4.17 🎀 7.17.19 🎀 3.27.21 🎀3.17.23
My usually level headed husband wants to use a car seat his friend gave us. It is brand new BUT IT EXPIRED IN 2015!!!! It's stressing me out because he keeps telling he I need to show him what's defective with it! But it expired two years ago!
I DO NOT, I DO NOT WANT TO USE THIS EXPIRED CAR SEAT!