You are on the right track. The secret is to ride the brakes, meaning apply enough pressure to make the brake light come on and the regen meter to peg its limit. I also engine brake by pressing the left paddle with the - sign on it to further add to the regen.
I also key off when in auto stop when parked, then shift to park before removing the key sothe engine doesnt refire just to be cut off again.
Lowering the car helps a few mpg, inflating the tires to the sidewall psi is good for a few mpg and blocking part of the grill.
If you drive at night you may find a benefit to going to some led and hid lighting. Not sure, but I think the fog or driving lights are on with the head lights where as they are optional on the insight and we have a switch. You can remove the drl fuse to turn off the drls.
Several insight owners have removed the rear wiper and replaced it with a hillman electrical plug from the hardware store.
Lastly, if you know anything about electronics, a PWM, etc your IMA system can take up to 12o volts dc and at least 17 amps that will increase your mpg. I had an enginer plug in kit that back fed the IMA system 117 volts and allowed a 15 mpg boost under regualr driving conditions.
