Car storage for the winter?

My mom has a 2006 Subaru wagon that needs to be stored somewhere in Boston for the winter. She snowbirds down to Florida and is leaving in a few weeks.

She's priced outa couple local areas, and they're asking $100/mo and the like. Anyone have a spare garage space or know of a friend or the like that can help out? Probably being stored through late April or thereabouts.

Thanks.