Wasnt real impressed right after I did the gotts mod on my 2001 5.4 2wd. Seemed like stock when driving through town, but just had a chance to open it up on some country roads and i must say the high end performance is amazing. Huge diffrence from 60-100 acceleration. Easy, cheap and well worth it. Took 20 minutes to install. Reccomend to anyone who wants cheap intake system

 

I have a 2007 STX 4x4 with 4.6. I did my own simple intake mod. I replaced the stock through fender air horn with a 3 inch piece of PVC through the fender and a 3 inch rubber coupler. You never know its there!
Under normal driving, you don't notice the difference, but when you put the hammer down, that's when you feel the difference, which makes total sense! I tow a 5500 (loaded) travel trailer, and it helps on hills and when you really the power.
It cost me nothing cuz I had everything, but you can find everything in the plumbing section. Just need a belt sander to gind down the OD of the PVC to fit through the fender.