Sounds like your dampers are mismatched to your springs and the rear is mismatched to the front. Have you tried going harder on the dampers in the rear?
Oh yeah! i have played with the rebound setting in the back and ½ a turn is too firm for the "beautiful" street of Montréal, but it rides quite nicely with only a ¼ turn. On the track, ½ a turn back and a full turn front and i am laughing in my helmet ;-) ... that is a smooth track. Streets of Montréal are something else
Canadian 2012 V6, MT, Perf.White Pony Package (3.31 gears). Koni Sport Shocks & Struts. Steeda Sport Springs w/HD Mounts, Route 66 SpeedShop 55D rear spring kit. Boss 302 Strut Tower Brace. BMR Adj PHB. BFG G-Force Sport Comp2. Pioneer TS-D6802R Front SPeakers, Clarion 80W/Ch Amp. JL Audio 8 Inch Sub And 175W Amp. GT500 Steering Wheel. 2012+ Tilting Headrests