my car is missing the splash guard but you really don't need it, just fabricate a plastic sheet of some sort under the intake / filter so you don't waterlock and bend some engine parts.

 

I forgot to mention, that picture is from a Mazdaspeed protege. The driver was driving in the rain and he parked his car. He came back about 2 hours later after the rain had cleared up and he started the car and it was sputtering so he revved it in neutral and it bent the um..... haha I don't have a piston engine so I actually forgot what it's called but the piston thingy you see in the pic that's bent. Turns out one of the pipes leading to his turbo got hot from the turbo. He had an EVO style hood and the cold water cracked it and it was fine while he was driving but when he parked it, it rained and water got in the intake. Then the turbo sucked it up and it was put into the cylinders and as you know water isn't very compresible especially under heat so ... that happened.

 

aww, poor piston rod! and poor vehicle! that mazda must be very sad as well as the owner haha. wait, i shouldn't be laughing