http://9glancers.com/index.php/topic,8974.0.html
HERE IS A BIT OF INFORMATION FOR ANYONE THINKING OF GETTING OEM MITSUBISHI MUD FLAPS FOR THE FRONT OF THE CAR:
They currently have OEM mud flaps available for the front of 2008 & 2009 & even some 2010 GTS Lancers that were made UP TO SEPT. 2009. If your car was made from OCT. 2009 to the present date.....the mud flaps WILL NOT FIT! Seems that Mitsu has redesigned the lower ground effects right at the base of the wheel well opening. It might be a little wider to some how "fix" the rocks being flicked up onto the paint. There is still a little bit of the tire sticking out, but not as much as my 08 did. So I am guessing that it will help. The rear OEM mud flaps will fit & they are being installed on my car as well.
I don't think that there is any change to the rears....so you should be fine.
2010 that was made before Sept/09
2010 Made in Oct/09 and after.
I can see that the newer lancer has slightly wider skirts...