SELECT date FROM table_26267607_2 WHERE winning_team = "Abt Sportsline" AND pole_position = "Mattias Ekström" AND circuit = "circuit Ricardo Tormo , Valencia"
Pada tanggal berapa tim pemenang ABT Sportsline dan posisi pole Mattias Ekström di sirkuit Ricardo Tormo, Valencia?
CREATE TABLE table_26267607_2 (date VARCHAR, circuit VARCHAR, winning_team VARCHAR, pole_position VARCHAR)