 Complete the following phrase:  From the opening of the track 1909 and the first 500 1911, through 1927. Carl G. Fisher and partners envisioned a proving ground for the budding automobile industry. The very early years of the 500 saw the track in its original proving ground intent, but the competition soon became the primary focus. Numerous makes and models of local, national, and international car companies participated, with the cars more conforming to the original specifications of being essentially stripped-down passenger vehicles. Riding mechanics were the norm with the noteworthy exception of Ray Harroun in 