splash shield keeps dirt, water rats and cats away from engine compartment... mostly.... maybe, some. but still better then nothing at all. Better to have in installed.
I assume, that you mean bottom engine shield just behind the bumper? like on picture #9:
Click on picture - it's a link.
also clips. I can't believe that there are 3 type of clips!!!! overengineering!!!
clip 19 (link)
clip 20 (link)
clip 22 (link)
without proper specs on the clips, it's hard to know their proper dimensions, unless you have the old ones and can measure them.
It's cheaper to get aftermarket ones from "other sources".