Don't like the livery by sms, some model only got empty livery or fake livery because of the licences issue... it will be nice if we could edit every car livery to what we like, for example like Malboro, Red Bull, Castrol, Bosch etc...I wish somebody could find the way to hack it.I don't know if we understand, why do you have to edit the "original" livery, just create a livery for the custom slot and use that.
With that said, the original liveries are not editable as far as I know.