A fun bit of information I completely forgot about until recently: there is some precedence for penguin having a duck car that also works as a boat. Batwheels makes the duck boat way cuter than it usually is, though. Because guess where it originally came from? Tim Burton's gothic masterpiece Batman Returns. Yes, Danny DeVito rode a giant duck around. And that visual sounds funny (and is kind of funny), but just remember this is Tim Burton we're talking about. His movies always are a bit off kilter. His duck boat looks like a prop from the nightmare before christmas or something. And that isn't a direct compliment. That is an acknowledgement of fear, because that movie terrified me for years (and still does a little bit).
Tim Burton is weird. His movies are weird. They're funny, but they're also terrifying. The actors are the things that save it. Like Danny DeVito in Batman Returns, or Catherine O'Hara in some of the only Tim Burton movies I can tolerate. Good actors can save a weird and frightening vision like those of tim burton.
PS: The duck vehicle also showed up in one episode of Btas. But there it was just a boat, not a car. And there it wasn't nearly as scary. Probably because it wasn't a tim burton prop. That had to have helped, i would think.