Like sales tax on a vehicle bought out of state.).

Based on it being Lakefront, it’s most definitely more attractive and more marketable than not, albeit on a small “non motorized boat” lake.  

Real estate is a very forgiving investment vehicle.

I currently work in the auto industry for Ford Motor Co.

Otherwise follow your state laws for abandoned vehicles.

Is there any law prohibiting me from using these security deposits ($900/renter) in a 2-year CD or higher bearing interest vehicle?

Making sure that all vehicles brought in have a title to match the drivers license...You could be storing a stolen vehicle otherwise!  

But My score hovers around 630-680 because I have a lot of new credit (not being used), student loans, a vehicle, a mortgage, several utilities in my name, etc.

You would not be pulling the funds out, your retirement account would own real estate (just like currently you can own stocks in your IRA, you also can own real estate in a retirement account, but must have correct vehicle to do so).

My problem is my credit is crap I cant even get a vehicle and i Need a new one bad mines on it last legs, I was wondering do private lendors lend money for personal use other than buying homes and what not?