To avoid violating the Rule of Threes you need to find food within three weeks.

Food is not standard equipment with any recent model sedan of my acquaintence. But scavenging such a vehicle might help you get some food.

What you are hoping to find or make are hunter-gatherer tools. So, hunting, fishing, and gathering, including digging are in order.

Any substantial metallic bit that is not too heavy for you could be a digging tool. Bar or rod bits can act as digging sticks, pickaxes, drills, etcetera, to penetrate earth, lever up stones, pry open woody plants, etcetera. Hubcaps, flat pieces, slightly curved sheet metal, etcetera, can stand in for shovels, hoes, rakes, etcetera, and when sharpened can be crude saws, pruners, eetcetera. Sharpening can be against substantial vehicle frame members or any handy roadway material, rocks, etcetera.

Digging tools can get you roots, corms, tubers, truffles, rhizomes, and a plethora of insect foods [yum!]. You can also dig pit and bottle traps typically effective to catch anything from rodents and reptiles to larger prey if you dig large enough pits.

Digging tools also get you bait for other traps, snares, fishing, etcetera.

Metal bars, such as the one usually found to prop the hood up, can be a formidable multi-purpose spear when sharpened. whether thrown or thrust, you may be able to subdue reptiles,amphibians, fish and mammals. If you find a metal bar or narrow strip with both strength and flexibility you may have the basis of a bow, when paired with a wire bow "string", and improvised arrows [from light metallic tubes like an antenna or light, straight plastic].

Wire can forms the nooses of snares to seek game of just about any size. You actively hunt reptiles and amphibians with snares on the end of longer pieces of metal [as well as wood and other things that might be available in the environment]. Wire can be twisted into fish hooks and gorges, with other wire used as your "line" if need be [think poke-pole fishing]. Wire can be used as tripwire for deadfall and other traps. Wire can be knotted or woven into nets to actively seine fish or create passive fish traps placed in streams or rivers.

Plastic and thin metal parts can be abraded and sharpened into knives, spear / arrow points, fish-hooks for fishing and snagging, and fish and frog gig heads, sling and sling-shot ammunition, etcetera.

Simply placing floor mats and similar scavenged material in moist areas often draws worms, grubs, and various insects under their cover. The morning harvest could tide you over.

Using you scavenged and crafted metal and plastic knives, if you found wood materials in the environment you could craft many other food finders. Such knives also let you clean and portion whatever food you have obtained.