I finally got the light to come on. The trick is, the pedal has to be floored (ie. actually touching the floor) and I'm not used to that because I always downshift long before that. I was thinking that it would be quite useless like that since pretty much anyone would shift long before that light came on, but then on the drive home, I randomly decided to put on my cruise control as I was going up a hill at 40 miles an hour in fourth gear. There's this one part of the hill where the incline isn't as steep and my upshift light came on and I thought it was pretty funny because I knew there was no way I'd be able to get up the hill in fifth gear. then a split second later, the light went off, and then soon after that came the steep part and the downshift indicator light actually came on! I think the only useful function of that light must be when cruise control is on and it's going up a steep hill, because then the cruise control floors the accelerator, and maxes out the ACCEL from the electric motor. I wish the light was designed to help out gas miledge instead but oh well, at least it does something useful

PS: I know some people think you should be able to "feel" the engine, but with these cars, the engine might tell your feelings you need to shift, and then the accel/charge kicks in and you reallize you didn't really need to shift at that point and should instead wait a couple extra seconds.