It has been established long ago that these have nothing to do with crashing or in game damage.
With the used cars, some of which have over 300k kilometers on them, you can see that an engine rebuild only gives a few percent increase in power. This means that an engine rebuild will never make sense from a pure money point of view.
As for the chassis thing, my guess is that this has to do with body rigidity. There are other mods in the game that affect rigidity, too, so we know it's something that is modelled in GT5. The real question, then, is how much does mileage affect the rigidity, and how much does the rigidity actually affect the handling?
Based on the small effect that the rebuild has on the engine, I would imagine that the actual benefits of a chassis rebuild are also marginal. Then again, this is dependent on how the rigidity actually affects the handling in the game. In the real world, the faster the speeds, the more rigidity should become an issue. But in Turismo, the faster the car, the more expensive it usually is, and the more expensive the rebuild, too.
Does anyone have any real idea how rigidity affects handling in GT5 (or even GT4)?
