That 100k warranty did not come until 2007 GM models.Wow....im sorry man, but as u probably already guessed, ur tranny is done. You have a 100k mile powertrain warranty...use it lol. I know for a fact that the 06+ Impalas all have issues with tranny's overheating due to insufficiant cooling of the tranny fluid, especially the SS. GM actually recommends buying an aftermarket transmission cooler for it b/c the little auxilary cooler on the side of the radiator is not good enough. I've gotta take mine in too b/c its slaming into gear from a stand still almost as if its not downshifting to 1st gear when it comes to a stop and its slide shifting for about half a second before it catches a gear when it downshifts on acceleration. I changed my fluid and it smelled slightly burnt before i changed it....smell urs and i can almost garauntee u that it smells burnt as well......they also have torque converter failure problems too, so look out for that too.