I’m trying to amke a Mitsubishi Lancer Evolution VIII car, but all of a sudden I discovered an error. You can see the error in the attachment.
How do I fix this?
Can you post a wireframe?
Sometimes errors like this can be caused by bad geometry
Yes a wirframe would be alot of help.
cyborg dragon-how come you dont post any of those works of art anymore???
Without seeing the wireframe, I would guess that selecting the problem faces and then using Set Smooth might solve the problem.
It could be that you have extra vert around those two places. You could try remove doubles found in w menu or carefully select the verts around the problem areas one at time and merge them.
Another option is that you can set crease value of opposite edges of those verts to 1 therefore messing up the smoothing.
Hmm… I have tried remove doubles, it’s the same.
I don’t understand what ou mean about this:
"or carefully select the verts around the problem areas one at time and merge them.
Another option is that you can set crease value of opposite edges of those verts to 1 therefore messing up the smoothing."
I just quoted it so you knew what I meant. 
Here is another look:
Attachments
Does ctrl-alt-shift-m select any verts around the problem areas?
You could try to reset the crease values (select all verts, shift-e, 0).
Are you using autosmooth or EdgeSplit modifier (found in CVS)?
.blend file would help a lot. All I can do is to guess now. 
How can I give you the blend file? Attachments doesn’t work…
You can host files in many places. One service, especially meant for .blends, can be found at http://uploader.polorix.net/ .
just set smooth/set solid until you get the right creases-also, selecting an edge you want to be hard and pressing V doubles the vertices there and gives a nice sharp edge.
Okay, I have uploaded it now. I used www.uploader.polorix.net as you said. My account is Killercop and the .blend file is called Mitsubishi2
Could you provide a direct link to the file please?
The edge angles seem to cause the smoothing errors. Try adding a subsurf modifier to the mesh and it will look smooth. Subsurf level around 2 will do just fine. Note that triangles may cause artifacts when modeling with subsurf modifier so I advise you to clean up the topology a bit.
By the way a mirror modifier can help you to model as well. Set the object center so that it’s in center of the car and then add a mirror modifier. This will mirror the mesh based on the center.