NASCAR drivers go to the restroom before a race begins so they don't have to go during the race, if they do have to go during the race they'll will just have to wait until after the race is over to go. They won't just stop racing to use the restroom because they're racing for their paycheck.
No they do not.
Most Nascar drivers have a straw to the right of them, or inside their helmet. Mostly they drink water or their sponsors drink.
In a Nascar Cup and Nationwide Series race there are 43 drivers. In a Nascar Truck Series race there are 36 starting drivers.
There are 43 drivers that start a Nascar Cup Series race.
Because it's how they earn their living
In the Nascar Sprint Cup and Nationwide Series, 43 drivers compete in each race. In the Nascar Camping World Truck Series there are 36 drivers.
43 drivers are in one Nascar Sprint Cup Series race.
No, they do not need a drivers license to drive a NASCAR race car.
The most drivers who could race in a NASCAR race is 43 right now. But back in the 40's and 50's it was about 60.
Nascar drivers generally have the helmet visor down during day races, in order to reduce the sun's glare. This gives the driver better visibility.
There are 43 positions in a Nascar Sprint Cup race.