Ok - here is the status when trying to enroll in CSR auto car rental memberships:
1.National ----- starting with Chase web site portal clicking on the National link --- that link previously notified of expired offer.
However, if you had made a "single reservation" the Executive Membership wa supposedly attached to reservation.
VISA Concierge agreed with me National was WRONG.
National has now fixed the link - at least when I tested it now works

2. AVIS - starting with Chase web site claims you get AVIS Preferred using 30% discount code ID: S107100
I was able to enroll but since i had a CSR CARD and was Infinite VISA card holder I was elevated to AVIS Preferred Plus and assigned a new code ID: S107101-02.

However, in a test booking a reservation with AVIS using discount code ID: S107101-02 that ONLY received a 10% discount.
Alerted Chase, Infinite VISA Concierge and AVIS of problems.

So I have corporate discount code that is applicable in US & Canada that is better than the AVIS Infinite VISA discount since I get free CDW/LDW and Loss of Use Insurance coverage with my corporate discount.
When I travel internationally "where applicable" I will use the CSR car insurance primary and AVIS Preferred Plus and trying to ensure I get 30% off offer. AVIS cannot advise where the 30% discount is applicable as you must make a reservation to find out. Offer is UP TO 30%......may be 0% is several locations.
Mexico was 10% off.