Just remember, you're bborrowing against Black Book value, and vehicles lose about 30% of their value each year.
There's a chance the next lender won't see enough value in the vehicle to pay off the current loan.
You'll need to talk with your current bank about your situation to find out if you qualify for refinancing.
If you have some savings and can make a lump sum payment so you're not borrowing the full amount of your current car loan, today's interest rate might be low enough to lower your overall monthly payment if cash flow is your issue.
If you're just trying to save on total interest, I'd say make the lump sum payment on your current loan and keep it as is... Or bump up your regular payments a bit so the loan is paid off faster.