GM, until now, has never successfully sold a sub-sub-compact in the U.S. But its Spark has bucked that trend, with 26,869 U.S. deliveries in its first 12 months, exceeding GM’s initial expectations by as much as 35%, per a source. The Detroit Three all gained share in the first five months this year, the first time that has happened in at least 18 years, as they sell some of their best cars in a generation.