Deleted mod shows as 'Missing Preview'

This is a very specific issue that I happen to know quite a lot about, so I guess it's time for me to finally create an account and write my first message, explaining what is causing it.
Imagine if you have 2 mods: one adds a vehicle, and the other adds something to the previous one, like a new part. What happens when you delete the first one? Obviously, the second mod won't work, because you can't select the vehicle it modifies. In this case, it shouldn't appear in the selector, because the mod only "turns on" after you spawn the vehicle. But in this specific case it's different. There are mods that add content to multiple other mods (example: Firwood Police Skin Pack). For them, once you spawn one of the vehicles that use this mod, it activates for all other ones, even for the mod vehicles you don't have. Since the mod can't find vehicles it's supposed to modify, it "creates" some of them itself (and I have no idea why it only works like this for some vehicles, and for others not). Since it doesn't create the preview images, it causes the issue you are having. Obviously it doesn't create the vehicle itself either, that's why it would probably spawn the default D-Series if you tried spawning it. In order to fix this issue, you need to either delete the mod that modifies the vehicle from the missing preview, or unpack it and delete just the folder of said vehicle (I'm not sure if you are allowed to do this kind of stuff, probably you would have to ask the mod author).
Now, you might be wondering, what kind of mod you have that modifies the Semi EU Truck? This is where it gets even more tricky.
The only mod I know of that does this is the Drivers, Passengers and Loads mod. You might ask, what does it change in the mod? It changes ABSOLUTELY NOTHING. Why does it cause this issue then? Because it does have all the files that are SUPPOSED TO add content (like with other vehicles, it adds a driver and a passenger), but they don't work. And the reason why is very simple. The mod always works by adding stuff to the Additional Modifications slot, which the Semi EU Truck doesn't even have! Why did the author leave files that don't work in the mod then? I might know the answer to this too. Both the Passengers mod and the Semi EU Truck were made by Synsol. He might have had another version of the truck on his PC that does have the slot, maybe as an update to the mod which he forgot to upload, and it all worked for him. This is just my theory, it might not be true. What I still don't know is why the issue with the preview image only occurs for the Semi EU Truck, and not for any other vehicle the Passengers mod supports.
Thank you for coming to my TED talk. Tl;dr: it's most likely the Drivers, Passengers and Loads mod causing this for you.