@Rob Z. Side note, I'd love to get into another rental but I have to free up some debt first
It is not the debt that needs to be cleared up but the debt to income ration that needs to be improved. This is according to you. If you bought a 47K car you must make some good w2 money. I would check with a mortgage broker and find out what your options are. With the right down payment and FICO scores they can push the debt to income ratios to 50%+. If you qualify use the cash as a down payment. If your ratios are off it will have very little affect paying off a 45K home loan (you can get another 45K home loan). Depending where you are at on the amortization schedule, need more numbers to give you accurate information. On the other hand a $750 car loan can get you a $140K home loan. Its all about the income to your debt payments. It comes down to your time line and goals. The car will need to be paid off before you can get a new mortgage. If you want to buy another property before 60 months you need to pay the car off.
I wouldn't worry about paying off the mortgages until you are done with acquisition faze of your life and you want to pay off to increase cash flow. If you have a rental I assume you have a primary residence. As mentioned before, obtaining new mortgages are based on income to debt payments. I would recommend getting a HELOC (home equity line of credit) on your primary residence. These have the most favorable rates and will probably be in the 4.5% range. They are usually interest only for the first 10 years making your payments as low as possible. Some banks under 100K are quick/easy qualify old school stated income (just did one a few months back). Very little paper work and verification.
What this does is allow you to pay off your car payment and take it from a $750 car payment to a $170 car payment (heloc payment) increasing your income by almost $600 and potential borrowing power for new mortgage to over $100K. Keep in mind you have done all this by keeping the $45k cash in the bank. Let's look at the net affect.
You apply for a 100K HELOC get approved and funded in 3 weeks (Don't pay unless you use the money). You take $45K from your heloc and pay off the car increasing your cash flow by $600. You now qualify for $110K new mortgage which will keep your payments the same as they were when you had the car payment. You also have the $45k of cash to use which brings purchase price to $155K. You also still have the $55K left in your equity line that you can use that brings your purchase price to $210K.
This is just an example of how you can purchase another piece of property without having to wait the 6 years until you pay off your car and build up another down payment. You will only have a $110K mortgage on your new piece of property and it should generate enough income to pay for the new mortgage as well as the equity line. You still have taxes and insurance but you will also have rental income to offset this. You also have the car payment savings of $750 that has been in your budget that could potentially make up any temporary short fall. Just be sure you know your numbers and it makes since.