The penalties for driving without registration, insurance or an inspection sticker in the state of Maine are quite steep. An expired registration will get you a warning and summons. If the car has not been registered at all or within the last 150 days and you are stopped by a law enforcement agent it will be considered a Class E crime. In Maine a Class E crime can allow you to be arrested and go before a district court judge. The maximum term for being found guilty of a Class E offense is 6 months.
Being found without insurance is a traffic infraction (and also a Class E crime) for which a fine of not less than $100 and not more than $500 may be assessed. Your license and vehicle registration can also be suspended. The suspension will continue until financial responsibility is proven and there are other requirements that might be compulsory. You might then have a restricted license for a period of time as well.
Being caught driving without an inspection sticker is a traffic infraction. Unless otherwise specified by the jurisdiction you are in, this again is a Class E crime, which is punishable by a fine of not less than $25 nor more than $500 or by imprisonment for not more than 30 days or both.
If you are predicament we can help you obtain auto insurance in Maine while you register and get your vehicle inspected so that it is road worthy.