2018 F150 stx supercrew 4x4

Hi guys been looking at a 2018 f150 stx Screw 4x4. went to drive it yesterday and got a number from the dealer. MSRP is $45875 with sale price of $39484. 36month/10.5k/yr $1200 down and $369/month. This was before any negotiation and the first numbers he gave me. I realize there are a few more pieces to the puzzle but from that info can anyone share any thoughts on how much realistically I will be able to negotiate down? I’m in NJ.
Additionally, I really like the stx and the one I looked at considering it has a spray in liner already but definitely not set on this exact VIN. Anyone else in the area hear of anything similar? Thanks for your thoughts

Sign it. If not get a tundra sr5 crewmax 5.7L sport from me for the same price!