 Complete the following phrase:  Throughout 1948 Cooper drivers took numerous class wins, race victories and fastest times, and demand grew. Occasionally, in these early years, Cooper himself sometimes drove one of his cars at a race meeting. Although he usually finished well down the order, the blow was softened by the fact that commonly most of the cars finishing ahead of him carried the Cooper badge. The Coopers continued to refine and improve their 500 and 1000 cars for the next decade, with demand boosted still further by the 500s eligibility for the international Formula Three rules introduced in 1950. American driver Harry Schell even entered a Cooper 1000  fitted with an expanded, engine  for the Formula One-level 