Before anyone else feels the need to put words in my mouth....
The Park Pack license agreement states that you may create a coaster which USES the park pack. You may upload that COASTER anywhere. You may NOT upload the OBJECTS with it, however. All you need to do is say "this needs the park pack.. you can get it here without signing up for anything:
http://tinyurl.com/6zdzd But that site is teh suxx0rs! so stay away from it!"
It's as simple as that. It's similar to saying that a map you made for a video game requires an expansion pack, or that a movie you made requires a specific codec.
And sorry to disapoint, but it's boxers... not panties.