it is suppose to be sealed for life
but iv drained and changed the whole tranny fluid on my ISF
the whole thing takes around 2 cans of AT fluid
yes it does make a difference
yes it compatible with the IS250
and no u cant watch DVD's whlie u drive
its a factory safety setting
you can get rid of it
but iv never done it to any of my NAV units
Mine does that alot now days
Doesnt really bother me
Iv been meaning to fix up this issue but iv just been lazy
Try using anti squeel lubricants on the brakes