The special thing about the OP coin (apart from it being probably the finest known example of it´s type) is that it shows Agrippina JUNIOR, last wife of Claudius and Mother of Nero, and not the "more common" Agrippina SENIOR, wife of Germanicus and Mother of Caligula.
Here is my Agrippina (senior) with the carpentum reverse: AGRIPPINA M F MAT C CAESARIS AVGVSTI - Draped bust of Agrippina Senior right, her hair waved and fastened in long plaid down the back of her neck / S P Q R MEMORIAE AGRIPPINAE - Carpentum drawn left by two mules, the hood supported by statues of standing female figures, one at each corner, the side panel decorated with dancing figures surmounted by stars, the wheels with six spokes. Sestertius, Rome 37-41 34,32 mm / 25,03 gr RIC (Caligula) 55, BMCRE (Caligula) 81-5 and pl. 30,5 (same reverse die), CBN (Caligula) 128-31 and pl. XVIII, Cohen 1, Sear 1827
