At first your upgrades will be quite limited but they'll make a huge difference, especially on your weapons if you took my advice above. (blog.us.playstation.com)
First upgrade for fourth - gen Mazda MX - 5 brings mild chassis, refinement and equipment grades, plus small price hikes (motoring.com.au)
Loot is scarce, so the nail board was the only weapon I had for the first three days, though it is possible to upgrade it at the workbench in your hideout after first upgrading your workbench. (coin-drop.com)