i have the coupe and the horns are behinde the fogs, Ive never replaced a horn before but i've seen custom ones at just about every auto store, i doubt it could be that hard, im guessing you would have to splice some wires and figure out a way to mount it, its not that heavy, you could mount it with just about anything if it wasnt a direct fit.
you can make your stock intake cold air just by taking out the vac tank out thats in the bumper, i guess you plan on taking out the tank anyway since you brought of the fog cover thing.
when i took mine out first i just plugged the vac line to it but when i reved the engine it sputtered so i took the hardware off the vac tank and left the wire running to it and just shoved everything up beside the battery and everything has been fine.
you can block the 2 pcv hoses to your air hose and intake manifold to make sure you get good oxygen rich cold air. hot steam from your oil doesnt make for a good burn, just make a breather on each head so vapors can still escape and clean air can still be pulled in when the oil cools. i actually got about 2 more miles per gallon doing this, but i drive almost allways on the interstate, your car will take alot longer to heat up through.
