I can't imagine that was very helpful. By the way, I think tutorials are overrated: most improvement comes from experience, trying over and over again.
The good thing about your picture is that you kept changes small. That's a good start.
The lowering job is not so well executed: behind the wheels there's a huge 'see through' gap, which should be filled. Also, if you lower a car this much, there needs to be a little shadow on the wheels, where the arches fall over it. My personal tip here: don't lower too much. But I guess I stand alone on this.
The window tinting is okay - in means of tint. But it seems you used a feathered selection, or no selection at all. This gives weird dark spots outside the windows, that shouldn't be there. Use a selection with a maximum feather of 1 px for these windows, or no feather at all.
About the new rims: I think the gold looks great with the blue hue - just not on this car, but that's just taste and you can't argue about it. The placement is off, though: the front tire seems a few sizes bigger, due to the alignment and size of the front rim. There also seems to be a negative camber on both rims, but more on the rear wheel. If you want to be secure about the placement of new wheels, put the opacity of the layer to 50% and align them exactly with the old wheels. Afterwards, put opacity back to 100% or it will look really silly.
'Creativity is intelligence having fun.' - Albert Einstein
