When Parnelli, the Firestone West coast distributor, was driving for the Goodyear West coast distributor Carroll Shelby, he covered the Goodyear sticker with a Firestone sticker

Both Parnelli and Shelby were Ford racing team guys, so Carroll had no problem hiring Parnelli

Can-Am 50th Anniversary: Flat Out with North America's Greatest Race By George Levy, Pete Biro