Original Member and FlyerTalk Evangelist
Join Date: May 1998
Location: Kansas City, MO, USA
Programs: DL PM/MM, AA ExPlat, Hyatt Glob, HH Dia, National ECE, Hertz PC
Posts: 16,619
I don't know what it takes in general, but I got Preferred Select through the AMEX Platinum Card.
It entitles you to a one-class upgrade when you rent based on availibility, which I almost always get. Usually I rent a full-size four-door and get a premium or an intermediate four-door and get a full-size four-door.