Giving a Car an Old and Grungy Look

Start opening an image of a car.

Create car selection using lasso tool. Press Ctrl+J to duplicate the selection in new layer.

From filter menu select pixelate>>pointillze.

Apply settings as shown.

Change the layer mode to linear burn and opacity to 30%.

Ctrl+select the duplicate to get the selection.

Form filter menu select noise>>add noise.

Apply settings as shown.

Change the layer mode to linear burn.

Select brush tool with the settings shown.

Create a new layer and apply the brush in car area with different colors.

Change the layer mode to soft light.

Select the top layer. From layer menu select new adjustment layer>>hue/saturation. Apply settings as shown.