There's only one thing I wish:
They'd include a "free driving" mode into the game.
There's so many little things in each level to look for (The poster in the Highway of the musical with Peach and Mario, Daisy's level having statues of not only herself and Luigi, but Baby Daisy and Baby Luigi dancing) and so forth.
Oh, and I am still slightly dissapointed that Captain Syrup didn't make her comeback. Maybe the next Mario Golf or Tennis game.