Well, even cars that are specially designed require stock parts, and they have serial numbers.
5 seconds sound clip from Knight Rider - Knight of the Phoenix (S1E1-E2).
You can hear this line at 01:06:20.722 in the Blu-ray version of the episode.
Quote context
[...]
- Oh, didn't Tanya tell you? I'm donating my share of the prize money to the charity.
- Well, each of us got a little donation for you too.
- Well, listen, guys, I hate to mention this, but, uh, I'm heavily trained in martial arts.
- I want that car examined from top to bottom, inside and out.
- Who Michael Knight is working for.
- The car is gonna tell us that?
- Well, even cars that are specially designed require stock parts, and they have serial numbers.
- I'm in jail. But it's a trumped-up charge.
- Look, I'm dead serious. The people we're after here are practically running the town.
- Michael, where is the Knight 2000?
- What do you mean you're not sure? How can you call me long distance and tell me you've misplaced it?
- I didn't misplace it. They impounded it.
- The trouble is, I think Comtron talked the sheriff into letting them check out the car.
[...]