Last day of a month is always a good time, and last day of the year is obviously better. However, the reality of it is, negotiations are only useful if they have a vehicle you want in stock. So to begin with, can you find one at a local dealer's inventory? Secondly, do you want to gamble on the off chance that it would be sold by year's end? I would argue that now's not a bad time to negotiate for the leftover 2012's. The 2013 are already available and the 2012's have technically been hit with the first year's depreciation(which according to edmunds.com is in the tune of 9 grand). With those 2 points, you'd probably get 4-5k off. I believe the invoice on that vehicle is in the ~47-48k range(IIRC, 37.5k invoice on base Prestige and 9.5k for Premium option) so TECHNICALLY you could get closer to that price but I doubt it. Jag/LR tend to not discount their vehicles in an attempt to control used vehicle depreciation. Also, print out some listings on eBay with similar specs. They'd argue that those are used but they usually have less than 3-4k miles on them and are 2012 so say you don't really care about the small mileage it has(and most inventory vehicles have some mileage anyways-mine had 800 miles and it's "brand new"). I had brought up those 3 points last month and got about 4.5k off.
I have been shopping for a 2012 Evoque over the last 10 days in Pennsylvania, and I got quotes on loaded Evoques after a little back and forth for $450, $500, and $500 over invoice from three different dealers. It was easy to get $2,500 off MSRP from most dealers right out of the gate.