How could I get someone to co-sign for a Vespa?

I want to buy a Vespa, and my mom said yes if I can get someone to co-sign... but her credit is no bueno, and my dad doesn't have great credit, my grandpa filed for bankruptcy, and my grandma has decided to no longer do that for anyone. What am I to do? I need a vehicle to get to my college classes, and I just need one, a vespa is very economic, i don't make much and so I need one, what should I do? I wouldn't feel right asking any of my friends' or their parents, but I guess I'd have to do what I have to do...