This reminds me of a funny story...
A younger 20-something buddy of mine, who doesn't exactly 'color bewtween the lines' outfitted his Chevy truck with a honest to god genuine locomotive train horn!
As per usual, Scotty called me one day and told me what he was going to do. I knew right away what this was all about, he 'aquired' this horn and was going to do this, with or without my help. Per usual, he wanted to pick my brain (he usually doesn't have the know-how for this type of thing, but knows what to ask).
I gave him some advice on how I'd go about it, nitrogen better than CO2, welding-type cylinder rather than air ride compressor, need for a regulator, mounting strap design for mounting the 3000psi cylinder safey, etc. Then came my usual disclaimer/lecture "it's most likely illegal, be very careful you don't give some old lady a heart attack or cause an accident with that thing" I'm sure he was rolling his eyes on the other end of the phone, but that is how our relationship goes... he does some pretty outreagious things (the Park City UT Olympic torch - FBI incident comes to mind), but he's a good kid that I try to keep from hurting himself and others. At the same time, I'm living vicariously through some of his antics that I myself aren't going to do.
He shows up at my house about a week later, w/truck, and literally rattles my windows with this thing!
He comes to the front door, one headlight literally rattled loose from it's mount and popped out of the bucket, and an old small windsheild crack 'ran' all the way across to the other side. Of course, he's grinning from ear-to-ear
Needless to say, my neighbors were not amused, but I sure was!