california compliant van trailer

I am looking to expand my area of operation. I currently operate out of Indiana and stay east of the mississippi river. I keep finding conflicting information with what I need to have for a legal van trailer for california. I read the california carb rules and understood that trailer skirts and low rolling resistance tires are required to operate in california. I was talking to a fellow driver the other day and he told me that those rules are only for companies that are plated or based out of california. Since I am based and plated in indiana I dont have to have trailer skirts and low resistance tires on my trailer to be legal in california. What do you guys say?