Beknet......I feel sorry for your situation and wish there was a magic wand that could solve it, but there isn't.
Even if this company provides a great contract protecting you, it's worthless if they claim bankruptcy, which they will ultimately do and then reopen as another company.
Even if things went well, the coach is still in your name, along with the loan. If the party they sell it to kills someone in a crash, you could be ultimately liable.
I understand this coach/loan is probably causing you panic attacks and has you concerned for your future. If you don't have the cash to make up the difference, then your best bet would be to turn the coach back into the bank. Consult an attorney and see how this should be handled, including bankruptcy. Either way, this is not going to end well. I would rather be in control of this situation, rather than some fly by night company who will have given your coach to someone that may take months/years to track down.
If you panic and do this, you'll regret it forever.