Sold an RV-- best way to get paid?

I would not give them my bank account number for a wire transfer. Unless -- go to your bank and set up an account that is to be used for this purpose only. They then can wire the money into this special purpose account and would not be able to gain access to any other accounts you may have. You could also go to an entirely different bank and open an account with the minimum deposit amount for a savings account and have it wired there. Again, no access to your other accounts.
Release the RV only after the bank has verified that the funds are there and good.