I don't think TakaraTOMY actually gives fans permission to produce/sell garage kits - I think it falls under Doujinshi (fan made comics, magazines etc) which are like fan sites - technically illegal but usually tolerated. But there are occasions where companies do decide to take legal action... remember the BotCon Japan 2000/Ichikawa controversy? (or ever wondered why BotCon Japan doesn't exist anymore) :/