The most expensive parts to replace on a car is the engine, transmission, and the total power train. You can purchase additiona coverage if your vehicle is newer. However, you are looking at spending a few thousand dollars for replacement parts or to rebuild the existing parts on the vehicle. Use good judgement. It can be costly fast.
The most expensive parts on a car to repair first off would be items in the drivetrain. Examples are your engine, transmission, rear-end. Some of the newer vehicles have alot of electronic compnents that can be very expensive like a computer board, brake control, or any electronic sensor for that matter
This will vary from car to car. Typically the MOST expensive would be the engine itself but in some cases these days the transmission runs a close second as far as cost.
The most expensive parts of a car to work is engine. The minute work also sometimes causes major expenses. Once the car is sent to workshop repairs will be more.
That largely depends on year, make and model. Most commonly, enginges and transmission repairs are most costly. Electrical components and computer chip directed items are the 2nd most expensive.