the store in toontown has the parts, too. and a store in hollywood studios has parts.
side note: at toontown i had a CM insist that i needed to buy a potato body in order to buy the parts. i said no, i had bought parts the previous year without a body and it was no biggie. the CM *insisted* i had to buy a body, so i left without purchasing anything. then at MGM (hollywood studios) i found another potato head stand, and asked the CM if i could just buy the parts and was told "of course you can!" i explained what had happened at toontown, because i didnt want to get anyone in trouble and wanted to be clear, and the CM at HS said i must have had a new CM because you can definitely buy just the parts. i knew that, having bought a box of parts (different ones!!!) the year before, but i thought maybe the rules had changed. so if anyone tells you you HAVE to buy a potato head body, you *do not* have to. you can stuff a box full of parts. and as long as they can tape it shut, you are fine.
we have quite the collection of parts! i love adding to it every year!!!