If you really want some horn power, go to
hornblasters.com
I got the conductor's special for my 92 Tsi and later got my girlfriend the same thing for her 98 GSX 6-bolt just with a smaller tank/compressor combo. Only problem is now her's is louder than mine because of the junk fittings I had to install mine with. I have since sold the car and kept the horns, I am thinking of throwing them on my 4g63 Elantra to scare people even more.
92 Tsi: This was my first install and I just wanted to get them in so I didn't plan anything.
PICS HERE
98 GSX 6 bolt: This one I planned for a while, spent a whole day welding the bracket and getting them to fit just right.
PICS HERE
Also, here is a link to the
hornblasters install gallery, both cars can be seen there as well.