Complex sentence: In the early years of his career, he notes, he had a wife and young son, whose gibberish attempt to greet his father while behind the wheel inspired the name of the man's truck ("Giddyup Go").
Split into simpler sentences: In the early years of his career, he notes, he had a wife and young son. It was the son's gibberish attempt to greet his father, while driving the truck, that inspired the name of the truck ("Giddyup Go").