 Complete the following phrase:  The 2017 Coates Hire Supercars Challenge was a motor racing event for Supercars Championship, held on the weekend of 23 to 26 March 2017. The event was held at the Melbourne Grand Prix Circuit in Melbourne, Victoria, and consisted of four races of 70 kilometres in length. It was a non-championship event, contested by teams taking part in the 2017 Supercars Championship, and was held in support of the 