... your alternator send power when you're in neutral.
I heard that the only real benefit to putting it in neutral was when you're leaving the car in the same place with the engine on for a good amount of time. Like when you roll into KFC and they tell you there's a 8-10 min wait for the chicken, just drop it in neutral and lightly hit the parking brake. Otherwise, its just a waste of time.
But detrimental? Not sure, just don't do any 5000 rpm drops.
im a stick shift driver...and with my is300..i have the same habit...i ALWAYZ put my car in neutral at a stop sign...and no it will not cause any tranny problems....you cause tranny problems when you speed off from a stop sign....
Ive read many differing reports on how this affects your vehicle long term. The one that I found interesting dealt with wear and tear on the car due to engaging, disengaging of parts in the tranny, and linkage issues. Example, Jane only moves for "D" to "N" 16 times a day. Dick however likes to put the car in neutral at stoplights, so he moves from "D" to "N" 200 times a day. Thats more than 12 times than Jane. If moving from "D" to "N" could wear anything out, John would wear it out quicker. It feels like quite a jolt on the system when You do this, but I can just imagine the plant that tests car components before they are put into production moving from "D" to "N" in an idling car via a robotic arm more times than a Real Human ever would as a durability test.