Complex sentence: This car is then thoroughly rennovated and heavily modified by Miyuki into a patrol car with the donated engine of the wrecked motorbike and various modifications that make its operation follow closely to that of a motorbike.
Split into simpler sentences: This car is then thoroughly rennovated and heavily modified by Miyuki into a patrol car. She uses an engine donated by the wrecked motorbike, and does various modifications that make its operation follow closely to that of a motorbike.