Please excuse the crudity of this model. I didn't have time to build it to scale or paint it.

6 seconds sound clip from the Back to the Future movie soundboard.

You can hear this line at 01:08:54 in the Blu-ray version of the movie.

Quote context

[...]

- Please, don't tell me. No man should know too much about his own destiny.

- You don't understand. I do understand.

- If I know too much about my own future, I can endanger my own existence. Just as you've endangered yours.

- You're right.

- Now... Let me show you my plan for sending you home.

- Please excuse the crudity of this model. I didn't have time to build it to scale or paint it.

- It's good. Oh, thank you. Thank you.

- Okay, now. We run some industrial-strength electrical cable from the top of the clock tower down, suspending it over the street between these two lamp posts.

- Meanwhile, we've outfitted the time vehicle with this big pole and hook, which runs directly into the flux capacitor.

- At the calculated moment, you start off from down the street, driving directly toward the cable, accelerating to 88 miles per hour.

[...]