Another new note, maybe worthless to some..
If you are outside of your number designated area, it is practice to announce such. For instance, in Moab, we are technically in 7-land. Practice says we are supposed to give our callsign something like this:
KCØPEG mobile 7, this is WØIIN mobile 7
Now, that may seem like a big nuisance, but it is practice. Remember, some amateurs look for those times when long range communications happen. So if all of a sudden a guy in western Utah hears a station from Colorado on simplex, he starts to pee his pants that the band has opened up for long range comms and runs to get as many contacts as he can before the window closes. Imagine how sad he will be when he learns later that you are just driving through his town.
It is not necessary, but it is considered courteous to announce the fact that you are mobile or portable when you are outside your area.