mortgage interest rates are lower but it's over 25-30 years, I would never ever recommend adding car debt to a mortgage and neither would my mortgage broker unless you are desperate. Could you go through Toyota or Nissan who offer 1% interest rates (or very low). That would be the way i would go. Look on red book for the trade in value also. You will never get close to the prices of cars you see on car sales in terms of trade in pricing. You wouldn't cover the loan with your trade in value.