Need to make a renal booking at LAX. Will have two drivers and wish to purchase supplemental liability insurance. Have executive status. When I go to book via the website of Enterprise I am being quoted a price which is about $40 more for the rental than I can get through either Amex (with platinum) or Capital one's (with venture X) portal for the same class of vehicle. Is there a downside to booking via a portal vs directly with the rental agency? I'm probably going to book a luxury or luxury elite vehicle so I am not sure the status benefits will make much difference in this type of rental. I would just buy the supplemental insurance at the counter if I book through the credit card portal?