Unless things have changed in the last couple years (possible, I don't keep track), GE can use the SENTRI pedestrian lane but a rental car in the auto SENTRI lane is (or at least used to be) a definite no go because the car must also be in the SENTRI approved database and be issued a SENTRI transponder thingy, thus categorically excluding a rental car from the auto SENTRI lane even though the driver may be OK.