Pseudo survey: Mobility guarantee

Moin! picked up my polo vonna inspection yesterday and already the day before, after I had been told what had to be broken or replaced and which costs would be incurred, I almost lost my power. so I got a total bill of 800€. and as I said, I drive polo, not phaeton or touareg. after a few months ago the motor control unit had to be replaced and this happened in the frame of the used car and mobility guarantee I was from the mob guarantee first al enthusiastically, but if you have to “buy” them so … therefore my question: how do you (especially if your car is still relatively new) travel with this topic? do you whistle on it, “buy it” you like me or or or … ?! am curious to answer your questions, since I have to weigh for myself first whether and to what extent cost and use are worthwhile.