yeah, bad call.
If he trusts you, maby he would let you use his plates to bring it home, and then drive the plates back in your burban.
However, In wisconsin, if you have the bill of sale and a title you're usually good. And if you had insurance on your previous car, or if your dad has insurance, usually insurance companys have a grace perioid of like a week where they cover your new car, if you are planning on insuring it. but only if you previously had insurance on a vehicle.
But, if you want it to seem less obvious, put dealer plates on it, not an "actual" dealer plate, but the "broadway ford" plastic plate or whatever the dealer, as then the cop wuld assume its a newly purchased car.
Its not a big deal if you do it calmly, but dont do anything retarded like putting a diffrent car's plates on it as that can get you in hella more trouble.
Just play it cool and bring your dad, having an old guy with you makes it alot easier if a cop starts asking questions.
Good luck man.
and we need some pics!