I get where you're coming from huey, and I have been known to play the devil's advocate a time or two for certain. That's why I wasn't saying the .308 bolt was a bad idea, just maybe that there were better options out there for the dollars spent to get an all around truck and beater rifle.
Truth be told, I sold my SKS Paratrooper back in '09 for a hefty profit, and turned part of that money into a Springfield Armory M1A Bush Rifle after the scare prices went back down. I don't always carry a gun in the truck, but when I do, that's the one I use now. Whether I'm camping a few miles North of the Rio Bravo in West Texas, or 12,000 feet up in the pines in Colorado, I've never felt outgunned with that rifle within sprinting distance. Have I ever had to use it in anger? No. Will I ever? Probably not. But it sure feels nice to know it's there. So, I definitely get the .308 Rifle thing, I've always had one, and always will. Heck, when we were taking trips as kids, my dad wouldn't be caught anywhere without his .308 M1 Garand Tanker somewhere in the car. I guess I came by it honest.
The OP said he was working under a budget, and I get that. We all are in some way or fashion. I see the SKS as a poor man's M1A. It will do just about everything the M1A will inside of 200 yards. It's less powerful, less accurate, and holds fewer rounds, but the same basic idea is there. Honestly, the main critters I carry a truck gun for are varmints, both the four-legged and two-legged kind. Neither one are that hard to kill, and the 7.62x39 has a long history of working well on both. The beauty of the Marlin in .30-30 is it will do all of that as well, and is still in a package that doesn't draw gasps of fear if the ignorant public eye catches a glimpse of it. That also could be a very valuable feature to have in this day and age.