Sing: I would look really hard for differences: different degrees of break-in; different weather at the two locations; different A/C usage; different terrain; maybe even different driving habits when you are in your own car vs a rental car; something. The different behaviors of the two cars seem much too great, in my opinion, to be accounted for by the options in the BC compared to the base-model. If you had reported a 5% difference in behaviors, I'd say, okay, sounds possible. If you'd reported 10% I'd say, who knows? maybe. But 2X or 3X differences, doesn't sound right to me.