Yes, that is my understanding, but I'm not positive. Since I use Amex premium rental insurance on all my rentals, I always have to add ANY additional driver to the actual contract in order for he/she to be covered. Thus, this wasn't something I thought to ask. If I have some time later today, however, I'll give them a call again and find out.

It's still a fantastic perk even if you do have to visit the counter!