This is a simple DIY I only had to do the driver side but I bought both sides - This is for a 2000 Infiniti I30 and this is very important to have cause your A/C unit and other parts will not get wet as you hit puddles and the water would splash on the parts then in the future rusting them sooner and soaking the belts making them squeal in the rain .
Yes they can be a pain in the ass to take on a off for oil change but if you can see you can slightly pull away from the oil filter and then remove it .
There are other splash guards underneath this vehicle make sure you order the correct one this one is for the sides behind the wheel covering axle sides .
Basically it is a bunch of clips that hold the parts - You can use clips or bolts which ever fits you .
More DIY at www.corollacarclub.proboards.com