An M44 would be the choice among Mosins for a trunk gun. the extra weight of the pigsticker will marginally help recoil, and when that 5 round mag runs dry, at least you have a spear!
Seriously, what do you want it for, where are you going to be leaving it, and how are you going to secure it against theft? If you are out in the toolies, and large animal protection is a must with a real limited budget, then a Mosin makes sense, with good ammo. If in a small/med town, real short budget, look at an SKS, the Yugo with still attached bayonet is a good cheap choice. Get the "unissued", for about $165, the shooter grades can have burnt gas valves.
If in major city, the concrete jungle, well, J&G Sales is running a sale on AK clone WASR10s for $299 right now.
Pay for something to hide/secure the rifle in your trunk, if that's where you want it, and make sure it is LEGAL to do so. To put it in perspective - there is no bugging out of prison.
If an M44 is all you can afford, that's OK, as there is something about those old Russian rifles - I have two myself. The fireball alone from a Mosin carbine can cook a felon at 20 feet.