The financing over ten years is the problem and I found that also. Excellent credit and a personal relationship with a local lender can help. Loans aren't easy like they used to be nobody wants to lend over 10 years for anything over about 8 years .. They may but you need sterling credit like 800 + .
One other thing , I don't believe the loan has be secured by the vehicle to make it deductible on tax returns you can claim the interest from anyplace as long as it was used for the coach. Even money from uncle "Jerry" can be deduct able I'm not a tax guy but that's what our accountant told us long ago.