True. If you could sell it and then obtain another vehicle without a loan at all that would be tremendous. That sounds like a Dave Ramsey solution from wwjdmsl.
Of course, one problem will be selling a vehicle that you are 'upside-down' in, which you likely are at this stage of ownership. Still, it may be worth a shot.
If you are determined to keep the vehicle, then the additional payment route is certainly going to prove better than simply making the remaining payments; especially at that interest rate.