I don't knwo if everyone is aware of this, but if you finance your RV, your interest is tax deductible. I am attaching a short article I found on www.bankrate.com:
What if your real estate circumstances are a bit brighter? Say, for instance, you're able to swing a vacation home on the lake. You're in tax luck. Mortgage interest on second homes is fully deductible. In fact, your additional property doesn't have to strictly be a house. It could be a boat or RV, as long as it has cooking, sleeping and bathroom facilities. You can even rent out your second property for part of the year and still take full advantage of the mortgage interest deduction as long as you also spend some time there.
But be careful. If you don't vacation at least 14 days at your second property, or more than 10 percent of the number of days that you do rent it out (whichever is longer), the IRS could consider the place a residential rental property and axe your interest deduction.
I hope that this helps someone who may have not been taking the deduction.