Live Streaming from The Pirelli World Challenge Grand Prix of St. Petersburg presented by Cadillac at www.world-challenge.com and www.motortrendondemand.com. On Friday, March 11, watch GTS Round 3 at 12:20 PM ET. On Saturday, March 12, it’s GT/GTA/GT Cup Round 3 at 9:35 AM ET, and GTS Round 4 at 5:1 PM ET. On Sunday, March 13, watch GT/GTA/GT Cup Round 4 at 3:15 PM ET.