I'm pretty sure you can only get Kleio's KP to 100 if you own a sports car
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. There's two ways to do this. Either you can start with a sports car (one of the options at the beginning), or you have to save a ton of money for a long time to buy the car. If you missed it in your current save file and have progressed to the point where you can't backtrack your save file, your best option is to do a NG+.
I don't know if Andrealphus is planning on adding another way to get Kleio's KP up to 100, but don't plan on it.