Tell me about the vehicle carry laws in Maine.  

Can you carry a pistol, or rifle loaded in the vehicle w/o a carry permit?  If so, is this only ok for travelers passing through, or everyday residents?

Also, do handguns have to be registered with the state, or local gov't?

AR-15 and AK rifles can simply be left on top of the dashboard with an extra mag sticking out of your 8-track player.  
 (paraphrasing one of the funniest lines I've ever read on NEHTF)

I wouldn't take legal advice from rgaper.  Whomever he is quoting is certainly a crackpot, too.

You need a resident/nonresident permit or be a LEO w/ agency approval to carry a loaded handgun in a vehicle. No one except some disabled hunters can carry a loaded rifle or shotgun in a vehicle. If just transporting firearms through the state then the Safe Passage Act would apply:
Linky

No registration for firearms.

I contacted the Maine State police and asked them the same thing. The Sgt.(Sgt. Gomane) who got back to me basically told me he refused to give me legal advice and to get ahold of a lawyer. He was a useless, condescending prick IMO.

I asked him what the statutes were and where I could find them online specifically(for example NH RSA 159:4- carrying without a license which can be found hereNH RSA 159:4). I also asked him if it would be legal to have an unloaded weapon locked in my Glove compartment as that is the only place that I can lock a weapon(my vehicle doesn't have a trunk). He kept giving me the same "canned" answer to lock it in the trunk and I repeatedly told him that I didn't have a trunk and asked if locking it unloaded in my glove compartment would be legal. That's when he told me that he refused to give me legal advice and to contact a lawyer.

He was a complete douchebag who made it seem that I was bothering him by asking a simple question, one that he couldn't be bothered to help with.

Handguns (or longguns) do not have to be registered, but as far as I know, traveling with a loaded gun is a big no-no. i've lived in maine all my life, and will be going back in the next few days. Even in the worst parts of lewiston and portland, you wont run into trouble where you should need a loaded firearm in your vehicle..... walking around in the worse-off parts of lewiston/auburn at 2am....maybe. but not in your vehicle.

Loaded long guns are a no-no.

Loaded handguns are a no-no unless you have a CCP.  To CC you either need a permit or if you have a hunting license and are actively hunting you may have a loaded handgun concealed.... just not in the vehicle.

do thay honer a NH ccp or do u need to get a non rez permit

I suppose on a nice sunny day, in dry road conditions you don't need seat belts. His right to carry has nothing to do with need.

OP- your best bet is a non-resident carry permit, easily done through the mail.

no Maine has no reciprocity LINK

That has been my experiance with all of the State troopers I have met, and I have had to deal with a bunch of them......

Maine statutes are viewable and searchable here.
http://www.mainelegislature.org/legis/statutes/

The only transport restrictions I'm aware of are in regarding to loaded firearm already mentioned in this thread.  Its my understanding that as long as the firearm is unloaded it can also be transported in plain view, without trigger locks or lockable containers, etc.  Those restrictions do not exist in Maine.

IMHO use common sense.  If you have a trunk use it.  If you don't, case it and store it where it's inaccessible from the driver's seat.  My objective would be to not stress out a LEO, so I would keep the handgun unloaded, out of sight, and out of my reach.  I would also not volunteer the fact I have a firearm unless asked, this being a recommendation of a LEO who instructs a local CCW class I help out with.