CREATE TABLE table_70706 ("Year" FLOAT, "Team" TEXT, "Co-Drivers" TEXT, "Class" TEXT, "Pos." TEXT, "Class Pos." TEXT)

Who was the co-driver in the DNF position in the GT1 class?
SELECT "Co-Drivers" FROM table_70706 WHERE "Pos." = 'dnf' AND "Class" = 'gt1'
SELECT "Co-Drivers" FROM "table_70706" WHERE "Class" = 'gt1' AND "Pos." = 'dnf'