Is it smart to refinance a vehicle to get a lower payment?

My wife drives a nice 2006 SUV that we pay a hefty chunk of cash on each month. Now my 10 year old car is starting to crap out and it looks like I will need to get something newer. Cash is tight and we were thinking of trying to refinance the wife’s SUV to free up some funds. Selling her car and getting something cheaper is not an option. Is refinancing a bad idea (assuming we could even get the loan in this environment)?