Cannot find any details yet but this was the proposal:
Proposed bodywork changes for 2017
2016 2017
Tyres Front 245mm wide thread 305mm wide thread
Rear 325mm wide thread 405mm wide thread
Suspension Track 1800mm 2000mm
Legs +/- 5 degrees profile incidence +/- 10 degrees profile incidence
Front Wing Wing 1650mm span 1800mm span, swept plan view shape
Endplates
Simplified endplate legality
Rear Wing Top wing 750mm wide, 950mm high 950mm wide, 800mm high
Endplates Rectangular endplate Swept endplate in side view and tucked in front view
Floor Steep plane 1400 max width; 1300mm min width; Edge radii <50mm constant 1600 max width; 1400mm min width; Edge radii <100mm variable
Reference plane Starts 330mm behind front axle Starts 430mm behind front axle
Plank Homogeneous Plank Pocketed plank for weight saving
Diffuser 125mm high, 1000mm wide, starts at rear axle 175mm high, 1050 mm wide, starts 175mm ahead of rear axle
Bodywork Width 1400mm max width 1600mm max width
Sidepods No constraint Swept leading edge in top view
Bardgeboards Big exclusion zone behind front wheels Reduced exclusions zone allowing for larger bargeboards
Weight
702kg max weight 722kg max weight + tyres (est 5kg)