cost of a car; car purchase price
Refers to the price of buying a car, not running costs.
The cost of the new car was higher than I expected.
carfare; transportation fare
Money spent on a taxi, bus, or train fare for a specific trip.
I gave him the fare to the station.
honorarium for travel; travel allowance
A polite monetary gift to cover transportation costs, often given at weddings or formal events. Usually prefixed with お (お車代). Sense 4 specifically refers to the custom at weddings for distant guests.
After the reception, we gave travel allowances to guests who came from far away.
I received an honorarium for travel as a token of appreciation for the lecture.
Compound of 車 (くるま, 'car, vehicle') and 代 (だい, 'cost, charge'). The reading くるまだい is a straightforward combination.