Qual é o chassi da Officine Alfieri Maserati com um motor Maserati Straight-6 e menos de 6 pontos?
CREATE TABLE table_name_55 (chassis VARCHAR, points VARCHAR, engine VARCHAR, entrant VARCHAR)
SELECT chassis FROM table_name_55 WHERE engine = "maserati straight-6" AND entrant = "officine alfieri maserati" AND points < 6