sactois350

So my 09 IS350 has 9k miles on it and and it pulls to the right but get this only when it's warm or hot outside. The car does not pull in morning hours or in evening hours when its cool outside. Keep in mind i live in northern cali....this time of year its about 100 during daytime and cools down to about 60 to 70 at nite and early morning hours. The alignment waschecked by Lexus today and its fine. I rptated front tires side to side and still pull to the right and rotated back tires side to side still pulls to the right. So I don;t think its a tire pull. Can it be sticly brake calipers or something else?....help please

ps...on hard acceleration it pulls to right