There are strategies how to use a car as weapon or armor, but none of them look like a medieval knight in armor. The outer metal sheets are much too thin to be effective.
Protect your body
If you want to surround your body with metal plates from a car, you need to use several layers (I think 3 layers as a minimum or your bending and ripping armor might injure you more than the initial blow). Even in 1997 car manufacturers wanted their cars to be inexpensive and lightweight, so they used the thinnest reasonably possible metal sheets.
The tires are far more effective as armor, but heavy and cumbersome. You need to cut (or saw) the sides away so only the tread remains. Tires have a steel mesh incorporated into the tread that - in combination with the rubber - should withstand hard blows and maybe even stop arrows. I propose padding the inside with material from the seats or doors and maybe add a layer of sheet metal on the outside to distribute the force of impacts to a wider area, decreasing the risk of bone fractures.
Cut the tires into a form like a bulletproof vest, then use strips of seat belts and glue to hold the thing together. If the glue doesn't stick, find something like a nail and use it to push the ends of the belts through the tires with a hammer and then tie them off.
Protect your life
Take that first aid kit with you! No matter what, you want that first aid kit.
Make a weapon
The problem with a short sword is its shortness. The risk of being injured gets higher, the closer your enemy gets to you.
Is there a crowbar or a long handle of a car jack in the car? There you have a very simple weapon with a range comparable to a short sword.
For an untrained person, I would suggest finding something that resembles a spear. You don't want to shape the outer metal plate into a spear unless you want it to be one-use-only. It will bent much too fast. Unfortunately, nothing in a car comes to my mind that could be used as a spear shaft. If there's a young tree with a straight stem nearby, cut that down and use it as a shaft. To make a suitable spear-point, cars quite frequently use cast steel for wishbones which (with a lot of hacksawing) could be made into a very serviceable spearhead. (Thanks to Ynneadwraith for the suggestion)
Instead you could tie a heavy object to the end of a seat belt and use that as weapon (like a ball-and-chain-flail).
Are there glass bottles lying around? (I hate people who never clean their car) Fill them with fuel, oil or pure de-icer, stuff some fabric from the seats into the opening and have your lighter at hand. You now have a molotov cocktail.
If you don't have a lighter, carefully open the car's battery and fill the bottles with acid.
Is there a fire extinguisher in the car? That can be utilized as a weapon, too. With some MacGyvering you could build a rudimentary cannon and load it with the remains of the wind shield or some batery acid. I'm not sure the fire extinguisher has enough pressure to blow glass shards very far, but you could very carefully extract an airbag and use that to propel your projectiles. (Airbags are dangerous and an untrained person could kill themselves by accidently activating one. They do pack a punch!)
You could also build a slingshot with a V-belt and maybe something like the headrest of a seat. Glue a little bowl-shaped piece of plastic to the belt and load it with the shards of a window.
I'm sure with enough time and the right incentive, you could find many more ways to utilize a car as weapon. But do you have to?
Be a Magician
If the story is about a man landing in the past or another dimension and facing the natives of this area, he might fare better by pretending to have macical powers. Things like a torchlight, fire extinguisher, space blanket or the car's horn would seem pretty magical to them. If you aren't strong, you better be smart.