J.W.
Ha! I did the same thing almost 4 years ago. My car was literally falling apart. The driver-side window would not stay closed, the hood of the car would not close properly, the front panel of the driver-side was missing, the windshield wipers were malfunctioning--all because my husband had wrecked my car and then refused to get it properly fixed. Anyway, my car was not just an eyesore, it was downright dangerous.
I spent almost a year trying to convince my husband that I needed a new car, while he spent the entire time blowing me off. So I did my research, found a car that I could afford and met my needs, and then bought the damn thing myself. He was pretty hacked off but I didn't care. I'd been driving myself and the kids around in a deathtrap and he was OK with that. I figured he would eventually get OK with the fact that I had a new monthly payment. (and he did, after muttering about it for a few months.)
You can probably haggle your interest rate some if your credit is decent. You can absolutely haggle on the price of the car. I actually got a better deal with dealer financing because they really wanted to make the sale, so they dropped the interest rate to .5% lower than my bank.
If you bring your husband, a lot of salesmen will talk to him instead of you. So leave him at home and don't be afraid to walk out if you get what I called "the little lady" treatment. I did not buy from one dealer specifically because the salesman kept discussing all the color options instead of answering my questions about the drive train, the safety record of the car, mileage and the warranty. When he suggested I go home and ask my husband what he thought before "we" came back and made "our" purchase, I left. I went to a rival dealer and bought my car there (and then called the obnoxious salesman's manager and told him what I'd just purchased and why.)
edmunds.com has good info on new cars to begin your research. Take test drives. The car I initially wanted to purchase based on its safety record was really uncomfortable to drive around. And if you have a subscription to Consumer Reports, they have outstanding info on cars.
I bet the other moms here on mamsource have some outstanding advice--can't wait to see what they say!!!
Good luck and GOOD FOR YOU!!!!!!!!!!