It sounds like a good place for fermenting lagered. You can always use a swamp cooler style setup (a large tub with water and perhaps some ice, which you then place your fermenters in) to buffer the temperature swings that occur.
The one thing to be aware of though is that while you will ferment most laggers in that temperature range, they still ideally need to be 'lagered', which involves dropping their temps to close to freezing and aging. Ideally you'd have a few days of diacytl rest in there too (higher temps).
See here for a conversation on ideal lagered fermentation schedules.. one thread of many: http://www.homebrewtalk.com/f13/lagering-beer-78842/
Sine the garage is so cold, it would also be a great place for fermenting ales, all you'd need to do is add a brew belt or similar heat source to keep the temps up a bit.