There are two types of vehicles in dayz. There are wrecks which just like buildings are scenery and/or loot spawns and there are working cars that may or may not be missing a battery/spark plug/radiator/water/fuel/doors/wheels. Wrecks are everywhere, working vehicles are rare and unless moved by another player are found/spawn in a select few places.

How are you trying to repair? btw, it's the Blow Torch now. That doesn't make a lot of sense.... but it's what to use.

Wrecked cars can never be repaired. They're wrecked.
2 of these cars are covered in rust. Those are wrecks.

So I play mainly on a limited official, no-mod server, only ten slots server. I am currently the only player.

I have visited all of the " working cars that may or may not be missing a battery/spark plug/radiator/water/fuel/doors/wheels." locations on my main server, and NONE are repairable. Many are not there or have become parts cars or "wrecks." I have also visited other servers with larger slots, 20 to 120 slots, that are empty, with no players, and it is the same thing. I have not found a working car on any of the servers I have visited. As there is no one else on those servers, and working cars do respawn after a time (I think it's 16 hours of real-world time), I doubt it could be other players. I have checked 26 servers, and it's all the same...

Cars Pre 1.21 all work, but no new vehicles are available to repair, or so I see.

With the freight truck, the loot from the Trucks is not even detected like it once was pre-1.21 patch. You have to aim the camera directly at the part to see it. You cannot process the tab on PC to see it in the parts loot in the vicinity of the player.

I am using https://www.izurvive.com/#c=-73;14;4 map to locate the working cars. If you have an updated map, please point it out to me, and I will use it to check the cars on my end.

I think you're looking for the wrong thing. The repairable cars are marked orange on the map, the grey ones are wrecks ( which can possibly spawn doors, hoods, wheels, etc. ). Usually next to the Orange spawn, there's a grey spawn as well. Meaning, next to repairable car ( dynamic spawn ) there's usually a static ( permanent ) one as well aka the car wreck. so you're mistaking a repairable car for the wreck...

"so you're mistaking a repairable car for the wreck..." I must disagree, as I have visited all or almost orange cars on the map... again NONE are repairable. I am trying again on a different server; if you have a better map pointed out to me, I would and will be happy to use that.

After 1.21, I can find ZERO "The repairable cars are marked orange on the map." Most are not even located at these spots marked on the map... others are there but are wreaking... I know you are used to dealing with stupid people... but I assure you I know the difference...

You obviously do not believe me, that's okay, I am willing to stream it to you live as I play.... on an empty server, if you have Steam... they are NOT present. I am making you aware of the issue... fix it or not... its up to you...

"Many are not there or have become parts cars or "wrecks."" This sounds very unlikely. It's not coded into the game. Repairable/drivable cars can never turn into wrecks. Because wrecks are static objects, basically part of the map. Just like the house is for example. Repairable cars are random like the random "loot".

Can you please screenshot the "non repairable" cars? Exterior + interior, and the location where you made it? So we can get a better understanding of what's going on here.

Do you mean one that should be repairable, but that is missing or has turned into a wreck, ya I can do that.

if it's a repairable car and it is wrecked (Ruined) It would be smoking and eventually despawn.

If it is a "Wreck" it is for lootable parts only.

Please post photos of what you're looking at.