I'm not really following what you mean, do you mean the problem is fixed?
My idea is that you said when you go over puddles in your car the engine doesn't run smooth. Usually if water is effecting the engine it is from the distributor, because it is making it give poor electrical signals to the spark plugs. If your running over the puddles and it starts running rough water is probably getting in your distributor. Just a thought.
140HP isn't really that much.....I mean it is a light car...but I can't really imagine it having much of a kick to it....maybe it's just because I have a V8
Well just think... a V8 car with around 300hp that was up in the 4000-5000 lb range might be about the same. Turbo models of this car approach around 200-ish I think from the factory. They are really built for carving corners though, and they have short gears.