If you are trying to register more than one crew person, you MUST REGISTER EACH PERSON SEPARATELY. You can't add them to your own entry. Trying to do so will likely result in messing up your own entry.

There are 2 ways to register someone else:

The person HAS AN EXISTING MotorsportReg.com account but is not listed in your account, you can ask them to Transfer control so you can register them. They will still be able to log in and register themselves but you will have the "shared" ability to register them for events.
The person DOES NOT HAVE AN EXISTING MotorsportReg.com account, you can create a “sub-account” (also known as a child account) for them by using the “Register Someone Else” link under “My Account” and register them that way.

If you need assistance linking accounts so you can register more than one person, please contact MotorsportReg.com by email or by phone, 888-242-9684.