AdvanceTrac Behavior

My 2000 LS8 is acting strange on the highway. To give a little background, I just bought the car with 56K Miles and I demanded that the dealership put new tires on the car before I took it. It had Goodyear Invicta tires on it and I drove it, they were nice and didn't squeel despite being bald. The replacements are Taurus tires: Continental Touring Contact P215\60R16 93T. The cars sticker and manual state clearly to replace the tires with 94V tires which is a higher speed rating. I took it out on the I-75 today and was running up to 100MPH with the flow of traffic :) Well, I looked down and the AdvanceTrac light was flashing like the system was active. I noticed the steering wheel was shaking a little (Felt like cheap tires). When I slowed below 85, the light went off and the shake quit. Well, I am pretty convinced the problem is the cheaper tires, but I was wondering what you all think. Also, I am writing a letter to the Ford dealership I bought the car from and I am going to ask for the correct speed rated tires to be put on the car since the manual says that's how it should be, if you have any ideas about how to convince them with or without a lawyer, I would appreciate it. Thanks guys.

I thought I would also add that these are the loudest tires I have ever heard as far as squeeling. I also had an 03 Taurus SEL with the same tires, they did not squeel like these do. I can get into a moderate stop, with the flow of traffic and the tires will scream bloody murder. It is very embarrassing.