Iryob9301 is very good to point out "out the door". I specified that on our negotiation and that is what we paid. They will attempt to tack on dealer prep, doc fees, etc. They will also attempt to sell you interior protection, exterior protection, windshield/tire protection, roadside assistance policies, etc.
don't be pressured into these 'impulse" purchases. Sure they make them sound hugely important and hard to refuse, but do. Unless you absolutely want them, say no. They can add thousands to your final dollar amt.
I negotiated 25% percent off our 2014 Tiffin. That was tax, title, doc fees out-the-door. We DO NOT pay 'dealer prep'. We took no protection plans either.
I heard, but do not know for certain, that mark ups were appox 40%. I figured 25% was good for me and the dealer.