There literally is no, "lets agree to disagree" in this case.
you stated "in any gear the car would be breaking the speed limit", to which it CLEARLY wouldn't, its not just my opinion that it wouldn't, its a FACT that it wouldn't.
Everyone is different and If you want to drive at a sedate pace, that's fine, that's absolutely great! But if want the ls400 to get a move on by taking advantage of the revs and redlining it, it clearly will do and it WONT breaking the speed limit on UK roads in the first 2 gears. It just wont!