I should have updated this thread a bit back. Yes, there is limiting on the 3 but it's not very severe. The power meter below the speedometer will show dots/hyphens on the right edge. I've seen as few as 3 and as many as 10.
I can say that if you go too fast you can start getting limited on regen or acceleration. On a (notably wide open) highway I managed to get about 2 dots of regen and acceleration limited since I just kept accelerating and using regen braking pretty aggressively on some rather hilly terrain. Didn't really feel the limitation though, since I wasn't actually flooring it the whole time.
Key things that may have contributed to this:
It was over 100 deg F outside and sunny
RWD, black colored car
Unless you're on the autobahn I doubt you would notice this significantly.