I have stock Pzero Neros on my car and roll empty trunk all winter. Just don't drive like a moron and you'll be fine.
More weight back there can also be a bad thing. You want more steering and brakes, not acceleration.
2013 Mustang GT - 402A GT/CS - 6R80 - Glass Roof - Engine Block Heater - SGM Exterior - CB/Miko Interior
Steeda Adjustable PHB (Street) and Steeda PH Brace, Stainless Works Retro Catback Exhaust...