Eh.. I'm a bit rusty but I'll try:
The vehicle is valued at its agreed value at the time of the vehicle's contribution at $20k. Although Historical Cost demands the vehicle to be valued at its original cost to ensure it is free from bias and error, the economic benefit represented by the vehicle has been partially consumed, and hence the future economic benefit provided by the vehicle is no longer indicated by its cost price. Therefore, the historical cost of the vehicle is no longer relevant to the firm. Instead, the vehicle should be valued at its 'agreed value' of 20k, as this amount is more useful for management decision-making by offering a more accurate reflection of the vehicle's future economic benefit to the firm.