Where to get heater to vent air ducts?

We use 3" rubber hose at work for air lines, it looks a lot like heater duct hose. I was going to use it on my car when I got to that point. Its a lot cheaper than $75.00 for eight feet. Its rubber and has a metal wire coiled though it. I'll have to get a picture and post it. Maybe it will work and we all can save some $$. The only down fall I could see is its a little stiff.