I had "Bob" put 18000km on my Redbull x1, the chassis actually got very very damaged, when he was driving Nurburgring straight, the steering wheel on the in car view was turned 45 degrees to the left, after performing restore rigidity 500k problem solved...
oh my bad.....
the rigidity improvement tuning part, makes the car more stiff throughout, which aids in keeping all four wheels plastered to the track surface.
I have noticed significant lap time differences, improved my Tskuba lap in 300hp mazda MX5 from 1:08.05x to 1:05.9xx three seconds difference, partially due to more laps in the car and partially due to rigidity improvement performed in between laps to test the theory.......