If your RV qualifies as a second home, then the interest is be deductible. You would record the interest as if you received a 1098 form. This is because the IRS form is geared to a second 'home', not an RV.
But boats and RV's can qualify as second homes if they meet the second home definition, and interest is entered correctly in the 1098 section to flow to the correct line on your schedule A.
I hope you find this information helpful.
