i dont know the atmospheric conditions...but i did buy the car used. when i bought the car the salesman told me it had gears and the mac-cat-back exhaust...and that was all he knew of. i dont know of anything else that could have been done to it. i have only added the other stuff in my sig. which includes the headswap,clutch,transmission, and lakewood control arms. these times seem to good to be true which is why i am wandering what my car really has in it.