Hi Longnan, 

You'll have to talk to the dealer(s) you're thinking about buying a car through. The rules vary from lender to lender, but they may require you to be a permanent resident in Ireland, never mind the fact that you'll need a sizeable desposit up front. I'm not convinced it would be the most economically sensible way to get a new car, either, as you'll presumably be giving it back at the end of the plan.