NASCAR Racing: Numbers, crew positions, car number

Question
Why do the numbers on the cars face the infield instead of the crowd......pit crew
positions, or rather, spotter?

Answer
The numbers used to face the infield because that's where the scorers were. Before computerized scoring NASCAR had a scorer for every car that sat (usually) just past turn 4 in the infield and wrote down the time that their car went by a line on the track, every lap. That was how NASCAR figured how many laps each car ran and verified  that the car was still on the lead lap or laps down. The number faced towards them so as the car came off the bank of the fourth turn the scorer could easily see their car number go by. I guess they just never changed that when they went to computerized.