BeardyThe Kiwi 3 is much smaller in size compared to Automatic. The size of the Kiwi 3 allows almost all users to have a flush look of the adapter plugged into their OBD2 port. Kiwi as an adapter and a brand has been out longer, and has more history of success than Automatic. Also, it transmits data faster then Automatic. Kiwi 3 works with more model of phones, including iPhone 4s and newer and iPad 3rd Gen and newer. The Kiwi is lower in price, Automatic pro, their best model is $130 Kiwi 3, the top model of Kiwi is $99.