Oh! We'd never find a smooth enough surface. Unless... Of course! Ice!
5 seconds sound clip from the Back to the Future Part III movie soundboard.
You can hear this line at 00:40:08.106 in the DVD version of the movie.
Quote context
[...]
- Bartender said that's the strongest stuff they got.
- Damn! It blew the fuel injection manifold. Strong stuff, all right.
- It will take me a month to rebuild it.
- A month? Doc, you're gonna get shot on Monday!
- I wish... Wait. I've got it! We can simply roll it down a steep hill!
- Oh! We'd never find a smooth enough surface. Unless... Of course! Ice!
- We'll wait until winter when the lake freezes over.
- Winter? Doc, what are you talking about?
- Monday! It's three days away!
- All right, all right, all right. Just let's think this thing through logically.
(STEAM TRAIN PASSING IN THE DISTANCE)
[...]