ARC Requirement?

I recently moved to Taiwan & am about 2-3 weeks away from having my ARC. I just sold my car back home & now have enough money to buy a scooter. My question is if I need my ARC in order to own one? I am planning on buying one second-hand from a departing teacher so is it possible that I just pay them the money & register with the DMV after I obtain my ARC or do I need to wait for my ARC to arrive before I make any moves to negotiate a scooter?

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