Could it be the limited slip differential that you hear/feel kicking in and out.

Never had any problem with either tour '07 Gt Vert or our current '11 GT/CS.

 

another possibility may be wheel hop. I got that on my old mustang when doing a burnout in reverse in the rain, it definitely made a noise

 

I don't have to hold mine for 5 seconds the icon with the car swerving comes on immediately.

 

thats only the traction control, advance track is still on if you do only this, advance track kicks in when you start going sideways/drifting.

to get advancetrac off you do need to be at a complete stop, and have your foot on the brake, and hold that button for 5 seconds straight and it will say advance trac off

 

i once tried drifting in the rain, not a good idea at all

 

were you actually trying or did the car try for you?
my old 240 loved to drift on me, wound up going backwards on the opposite lane once after a snow/ice storm, lol

 

I guess wheel hop is what i am feeling, like a jackhammer in the trunk. On dry pavement theres no hop at all. What about slick roads would make this happen?

 

If you can't distinguish wheel hop from ABS/ESC you probably should not be driving the way you are....especially in the rain!!!

 

If one has never experienced the two and had them explained, one may not know what is happening and could then end up questioning the incident on an internet forum......and actually find the answers and become a better driver because one understands one's car much better.

 

100% fail safe. Advanced Trac cannot be turned off 100%. It stays on in the background ....... kinda like big brother looking out for you even tho you don't like it. call Ford and bitch, tell em you will not buy, and others will not buY their crap. either that or buy an older model!!!!!!
Best of luck with your 2012, my 07 spins whenever I want !!!1