Unless I'm reading something wrong, your gross income is $9166 a month, which means you have $4166/month left over after your monthly expenses, that is a pretty great savings rate. I would definitely use that to pay off the vehicles first if you plan to keep them both.
I agree with Zamboni, worry about what you can adjust rather than worrying about your spouse. You don't mention any long term goals...are you wanting to retire early? It helps to have your spouse on board, but I think you will fare best by just setting the example and taking steps to get there. If they jump on board, great! If not, you can still work towards it yourself.
Should I get rid of my car and get a cheaper car? If so, any suggestions?
--you can buy a nice used, older car for the $5k you have invested in your Carolla. Getting rid of that debt may make you feel more secure in where you are at currently, as well as demonstrate to your spouse how serious you are about saving. It doesn't seem like the car itself is a priority to you anyway.
Should I pay off one or both cars? Yes! That is what I would prioritize in your situation. Get rid of the debt, then throw everything towards maxing out your retirement, as Zamboni mentioned.
Can I keep my gym membership? Better to spend the money on your health on the front end than the back end ;-)
Suggestions for best cell phone companies? I like AT&T. Not the most frugal option, but I pay ~$60/month for 6GB of data, unlimited texting, and some calling minutes I never use, it's more than enough.
Frugal high protein meals that don't involve beans? Buy meat in bulk when it's on sale, prep and freeze it. I love rice and beans, but it doesn't have to be quite so dire! Eggplant, pasta, chicken, are all easy things to cook at home. Do you grill? That can add a lot of variety in flavor to things you normally would cook in the oven. Don't spend on alcohol when you go out to eat.
Any other ideas?
Your idea to shop around for car insurance is great, I would definitely pursue that.
I wouldn't push the idea of moving on your spouse, if they bring it up later, great. It doesn't sound like that's a big problem area for you anyway.
Any way to boost your business income easily? Don't forget free sources of advertising like social media accounts.
The $100 on home supplies seems high...maybe cut that by looking at cheaper store brands?