It is required that your car numbers are at least 8 inches high, and of a standard legible font. Class letters need to be at least 4 inches high, of the same font as the car numbers. The club prefers the numbers and letters to be white or black, but not mandatory. What is mandatory is that the color of car must be of opposite contrast to the number/letter color. For example: A yellow car with black numbers is good. A yellow car with white numbers, not good. This rule applies to both magnetic and vinyl (semi-permanent) numbers and letters.
Rule of thumb is that you should be able to make out the car numbers and class letters from at least 75 feet away from the car (about 40 paces). This is about the distance the course workers will be from your vehicle while it is on course.
There are paper class numbers and letters at registration check in, if you do not have numbers or letters. Please tape the numbers and letters in the designated areas of your vehicle during Autocross events.
If you are attending more than one event per year, it is recommended that drivers obtain magnetic numbers and class letters, to help keep the cost of printing down for the club. You can go to any sign shop or graphics shop to get this made up. Typically, It will run about $50 for both sides of numbers and class letters. It is also recommended you purchase a pair of “1”s as well, in case you ever have a co-driver.
Car Number and Class Letter Placement Guidelines
CAR NUMBERS AND CLASS LETTERS MUST BE DISPLAYED ON BOTH SIDES OF THE VEHICLE.
The class numbers should come first before the class letters. Below is a depiction of both the door location and rear quarter window location for number and class letter placements.