Best Options for Auto Loan?

I have a current auto loan that I have negative equity in, currently upside down about $7,500. I’d like to refinance it to a lower interest rate but pay the same amount monthly to help attack the amount I owe. Should I apply for refinancing being so far upside down? I also am wanting to apply for a car loan in January for a new car as I don’t like my new car and hope to only be upside down $4,000 by that point and put down around $6,500. Will applying for refinancing or getting refinancing right now hurt my chances of applying for a new car loan in 7/8 months?