For what it's worth, there's an outfit in Glendale, AZ, that claims to
have several successful installations and claims to be a going
concern:
http://hydroforce.synthasite.com/. I've talked to the
principal, and he sounds on the level. The website has statements
from a few satisfied customers. He quoted a price of around $450.
I've attended the "show & tell" meetings of users, mechanics, and
interested onlookers (like me) at Woodley Park in Van Nuys. When
gas prices went above $4 last year, the numbers in attendance
appeared to be upwards of 100, and the cars with systems installed
ranged from 3 or 4 to about 10 -- all models & types. Except for the "Water4Gas"
car, with a system based on the books by "Ozzie Freedom" (not his real name),
the rest all appeared to be locally assembled by guys who offered to
install them for about $1K for a V8.
There's also a Canadian outfit,
Canadian Hydrogen Energy Company @ The Hydrogen Company.com,
that has been marketing hydrogen injection systems to the long-haul trucking market
for several years. They claim to have more than 1M miles of testing behind
their product. Their price tag: $5K. Or that's what it was when I checked last yr.
Argus Okie