Well, I guess to the topic of this thread, and I am not being a smart **** or anything, but why would you want your truck to be like a big rig? I guess I never understood making something seem like something it isn't. Like sticking SS stickers on a non-ss car, etc. etc. etc. I guess I just don't understand why you would go all that trouble just to get an airbrake sound. Want to impress me, install air brakes!
I like and have air horns, but mine are not even like the "big rig" horns, they are a much higher note and really much louder, I didn't install them to be like a big rig, just wanted more horn. I think the air compressor, electric or mechanical is a good idea, but just don't get the other "sound" options. I suppose if you had an air actuator to lock the parking brake, that would be cool, but just to make the sound...