Mr. Spallino, a 40-year-old executive at a California construction and engineering firm, and his wife, Sandy, have been leasing the FCX for $500 a month since July in one of the more unusual experiments in the auto industry's history.
The Spallinos, including daughters Adrianna, 11, and Anna, 9, "aren't just the first fuel cell family on their block," as one Honda ad recently put it. "They're the first in the world.