I understand the the new law makes it to where you cannot add additional seats to a 2 seater but I thought I heard they grandfathered in older models? What is the year cutoff and how does the law read for wearing helmets? And lastly if you install a child car seat do they have to have a helmet too? Our friends have a 2011 or 2012 Rhino with a full roll cage and seatbelts for everyone. Looking to bring it this coming week to Pismo and just want to make sure we are following the rules. Thanks!