Solixo

I just purchased a used 2010 Fusion SE V6 and I love it!! I did notice, however that it does not have a locking gas lid and that it doesn't seem very well attached. I've tried to feel around in there for a screw that may need to be tightened, but cannot seem to find one. Does anyone else have the same issue, or do you know a fix to it? I understand that this is sort of obscure, but it's been bothering me.