I agree about the Vallelunga, just a shame the engine was the rather dull 1.5 litre Kent 4-pot!
This was a great challenge - I did think DKW at one point (for the rear 2-stroke engine) - as well as Lancia (for the front end) but credit to those who got this one.
Just shows that for me some of the best quizzes are the ones I don't know!