Pay off your car loan. Here is why:
As you mentioned, the interest on your home mortgage is tax deductible. This may not completely offset the difference in interest between your two loans, but it makes them much closer.
Once your car debt is gone, you have eliminated a payment from your life. Now, here's the trick: take the money that you had been paying on your car debt, and set it aside for your next car. When the time comes to replace your car, you'll be able to pay cash for your car, which has several advantageswhich has several advantages.