Apologies if this has already been asked but I've looked through the other additional driver threads and can't find what I'm looking for.

I've booked a car to pick-up at LAX next month (Gold service). I need to add an additional driver who is neither my better half nor co-worker. I understand that I can stop by the counter when collecting the vehicle to complete an "Additional Authorized Operator" procedure. However, ideally I would like to avoid stopping at the Hertz counter altogether if possible so we can get on our way without any delay. Has anyone had any success adding someone (other than spouse / co-worker) in advance? Can I visit my local Hertz office in Spain with the additional driver to complete this procedure? Any advice greatly welcome!

I tried calling the Hertz customer service line but was in a queue for 20 minutes and the call was still not answered.

Thanks
Latitude40