splash guard

Hi: Checking to see if anyone has experience adding the mud guards to their vehicle after purchase - these are the GM OEM mud guards I'm talking about. Anyone else add these after purchase because the vehicle didn't have them? I've got them on order and I'm looking for gotchas and tips on...

I have a 2001 LeSabre. I am trying to get to the inside of the left front fender (my son created a slightly modified profile to the existing outline - using a fence post he didn't see). The damage is not massive, but it is noticeable. I am going to correct what I can with a 1x4, a cloth, and a...