I built a cold air set-up that still draws from the hole where the pcm rests (it is a sealed box inclosure around the new cone filter) and have about 90 dollars invested. it took 3 days of testing and fitting to get it to work properly and the box to seal to my high standards and in the end I got 3hp on the dino with little to no torque, so it really wasn't worth it (it was a pain in the blank to get everything to pit proporly) but it does make what people would call a "cool" sound. to sum it up just run the factory set up with a good high quality filter. my new set-up does use bigger 4 inch intake tubing with a spectre cone filter thats about 10 inches long, the tubing I used is welded alumium (I'm sure I butchered the spelling on that) (the tubing is insolated to help with heat), I used welded because the mandral belt tube I got which I'm not including in price because I didn't use it (it was EXPENSIVE) it didn't want to fit because it was to long on the bend. But with my custom magnaflow exaust (which makes it sound better than most mustangs and camaros), custom built engine cover, and front slotted rotors (which were a dealer add on from GM performance which I think is pretty cool) and the few other little goodies on my 99 Eldorado I can impress a few people and get some enjoyment out of it which is all that I care about. and one last thing I did for this set-up (execpt I did it on my 98 Deville) was cut the factory tube and use that instead of the 4 inch aftermarket one because there is more room to get it put on the MAF sensor housing but in the Deville I found there is slightly less engine room so I had to make a different box inclosure and only use a 8 inch long cone filter, for the Deville I there was not hardely a hp boost so it was really not worth it, I just did it because I had a spare tube laying around with my bunch of extra parts. So again I just recomend running the factory set-up with a high quality paper filter (I prefer wix or if you want the oiled spectre ones are a good value if you really don't want a paper one) because on the Deville there really was no performance increase and on the Eldorado there was one but it wasn't worth the time and money I put into it because I can't stress enough how much of a pain it was to get everything to fit and work properly.