I remember getting my stocko 260z up to 200kph, which is about 125mph your speed. (Funny thing is, the car wasn't fully wound out in 5th yet.)
And that was down a busy highway (my highways busy is no where near as busy as the american highways) and yes, I shat myself and thought i'm never going to do that again. Cause the front end of the car was so light it wasn't funny.
From that little experience i've come to the conclusion that, no way i'm going to that speed again the way my car is atm (totally stock pretty much) and i'm not going to speed that fast down the highway again.