Hmmm had my car down "a runway strip" this morning and clock was indicating 145mph. How accurate are the speedos on these cars? Also what's the standard 0-60. I know mines been superchipped but this morning I beat a 525 BMW and a Lexus LS from lights, and I mean easily. Do you also find the short gear shifts in the Astra help it get off the lights quick? Response time from them is good too. Traction control really helps.