If you can pay up to half of the total amount payable on the agreement, you should be able to hand the car back to the finance company. This is called a Voluntary Termination. If your car is in good condition then this should be no problem.
This aside (unless you have Protected Payment Insurance) you could be stuck with it unless you obtain permission from the Finance company to sell the car and repay the loan with the capital raised from the sale.
JJ
You gotta tie yourself to the mast my friend, and the storm will end.