In re-reading your post, I'm seeing the trustee has already offered you terms of repayment of $915/month for a total of $11,000.00, correct? If that's the case, it's probably the "bottom line" the courts will accept, regardless who purchases the autos. It stands to reason they'd like to see more from a public sale, but I'd lay odds they've already offered you the "best deal" you're going to get. (Without having the 'particulars' in your case, I'm just offering a possibility here, but it could well consist of the final, settled payoff amounts.) It's also probably a more manageable monthly figure than any reaffirmation agreement I previously mentioned, given the "only" you posted above.

All of this can be confirmed with your court appointed trustee. Ask him where the figure came from. When it comes to acting outside the boundaries of the bankruptcy, I think all questions should be directed to the courts first and foremost, so you don't inadvertently jeopardize your position there. If "coming up with more money" would include undisclosed assets for example, (part of the 'shell game' I previously mentioned) you could find yourself a in real legal and financial nightmare. Talk to your trustee...or at the very least, a bankruptcy attorney. *Personally, I'd recommend you try your trustee first to keep out-of-pocket expenses to a minimum.

Hope the clarification/additional suggestions help. Again, good luck.