squirelly drive

[BYprodriver]

Mechanics generally speaking know very little about tires & believe some of the same old myths that have endured for decades & misinformed so many people. Until new tires wear off the mold release compound & excessive lubricants there to preserve the tire during storage the tire will not have traction capabilities it was designed for. This requires 100-500 miles of driving to wear off.
Potential cause #2 Hi-performace tires like your's rubber compound is designed for outside temperatures of above 40F degrees. Traction is considerably reduced below 40F.

If neither of the above applies to your situation that seems to point to the alignment settings, although anytime you are in a high speed turn with heavy throttle application & lift off the throttle quickly, you are shifting weight off the rear tires, toward the front tires. This quickly removes traction or grip from the rear tires & transfers traction to front tires.

[stephen wilson]

The fact that it's induced by the throttle makes me think an engine or transmission mount is loose, or failed.

[Topless]

Pushing the car hard at temps below 40F is a recipe for "squrrelly".

https://www.google.com/search?q=weather+ontario+canada+today&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-USfficial&client=firefox-a