How can I get mold out of my trunk?

I have mold in the trunk of my car and I need it out. I have two small children (3yr old and 7week old) and I'm allergic to it. My car was being fixed and I just got it back two days ago. When I got it back I got congested and couldn't figure out why. Well then I thought about it and that's why. I get very bad headaches and my nose gets clogged while sneezing constantly. Any suggestions on cleaning it out? I'm on a very low budget so low costly ways would greatly be appreciated. Thank you!