Any mice in the car ? Look for mouse poop in the trunk, under the hood, under the rear seat and inside the car, they may have chewed on some wires. I store mine with moth balls under the car and under the hood, Lavender scent inside the car and trunk, Lavender car fresheners or dryer sheets...
Do you still have the Barton shifter and if it will work with the 2013 GT mt-82 6 speed, 2013 5.0 deep impact, 4 posts down from you may be interested in buying it.
I use Royal Purple in my Engine- Tranny+ Diff. makes +6rwhp. I don't drive in cold weather, but it does shift smoother in the warm weather than it did with the stock stuff. Call the Guys at Royal Purple 1-800 882 0890 and ask them if it will help with your cold weather shifting.
Does it come with the mesh+ fog lights and do they work ? The mesh look a little bent in the pics. When you talk to Mr Body Kit on your return, maybe you can work a deal on the Roush stage 3 kit, I saw it on there site .(Your the unhappy customer from NYM with alot of friends that buy body...