The 1.9T engine is pure Volvo. It is based off of the modular family of Volvo engines that started with the 2.9 liter inline-6 that was first used in the 960 in 1991. The inline-5 is based off of the inline-6 and the inline-4 is based off of the inline-5. They only real contribution from Mitsubish is the frame and not much else. I think the negative criticism comes from people who really don't know the facts, although I do think that diehard Volvo enthuisiats do feel a little Japanese influence in the car, which is not that much at all. With the right set of wheels, the S40 is a sweet little car.
-Drew
-Drew