ECR question on car number

I remember at some point a car number being required on the back of ECR cars. I'm looking at running the NSS ECR in June (will be my first ECR), and after looking the rules:

http://edgetiming.com/SEDIVECR/08ECRRules1.pdf


I don't see a requirement for rear numbers anymore.

Also, any advice for a first time ECR entrant is appreciated.


Thanks
Eddie