Help buying/selling a vehicle?

I need help in buying and selling a vehicle, my husband and I are going to have a baby very soon and we need a reliable, comfortable car. We live in California and my husband is in the military and he doesn't get paid much because of his rank. My husband's car right now is very unreliable and is not good for the baby at all. He can't sell it because the car is in his mom's name and his mother lives in Arizona, she doesn't have time and doesn't know how to get it notarized so we can sell it. I would like to get a nice car, is there anyway that they can help military families?