Found an interesting page on a DIY Bluetooth helmet mod. Much cheaper than the $200+ kit from smith.
I already ordered the headphones on ebay for me (Vantage) and my GF (Variant Brim) helmets. I've always just used a corded DIY headphone which never lasts more than a season, probably because of all the movement and falling. Also tired of taking off my helmet and having to disconnect it from my phone when i stop for lunch with friends, not so much a problem by myself as i never stop.