basically title, this has happened with every single model I’ve used and I don’t know what’s causing it, I was confused but after trying the same thing with other models I realized it is the object I start from
It looks like the body of the car uses a different material than the wheels seats etc. (could be a different object altogether I can not tell from the screenshot)
At any rate it always means a texture is missing or Blender is looking for a material that does not exist or is not linked.
Take a look to find which is this is
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open the image editor and see if any of the images are blank.
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open the shader editor and make sure all images are connected, if they are, make sure the image is selected in the node.
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Read the manual!
https://docs.blender.org/manual/en/latest/render/materials/
https://docs.https//blender.org/manual/en/latest/render/shader_nodes/textures/index.html
- search the internet
Welcome 
…
if you show your shader setup for example like so:
then the everyone might have a look what you have done and so some suggestions could be done “faster” / more precisely according the “wrong material” 
? For using multiple materials on a model you maybe have to double check where you added the textue (and how).
Could it be (while showing the paint mode) you forgot to generate an image for the image texture node ?? Because with a missing image it would show this pink “warning color”.