As the PP said, the easiest is method is to pay for valet at the Poly ($15 plus tip). You'll be able to leave your car at the Poly all day and the take the monorail back at the end of the day. Once you pay for valet, you can valet the car at any of the other Disney resort for the rest of the day without having to pay again.
Otherwise, you can park at the TTC and then either take the monorail or walk to the Poly. This will be the cheaper option ($14), but it'll take a little longer.
The last efficient option is to park at the Poly for breakfast and then move the car to the TTC after breakfast.