Unless your friend wants to void his warranty, I'd seriously think twice about making such a mod/addition to the car. I too have an '04 Civic LX and was contemplating making a few changes to the engine and suspenssion. Suffice it to say I'm happy I called Honda and my dealership and they both confirmed such changes would void the wrranty. At this point, with the car being as new as it is, I wouldn't make any major changes. He may never use his warranty, but it's a heck of a nice safety blanket to have.