i have an 05 lly duramax and i love it and the chevy has the best ride and interior and allison trans. ford has engine and trans problems, dodge has trans and electrical problems. i know these for a fact. as for buying outta state i think you have to have a certain amount of miles on it to reg. in california. as for tax and license i am sure cal. dmv. will nail you eventually. i think most cars trucks are made to follow california smog regulations.