Re: Karmann ghia gas heater?
Be sure to get all the brackets and pipes. The heaters are all the same but each model of car needs special mounting brackets and duct work. A few pics and measurements will help with cutting the holes. I've seen templates for Beetles but not Ghias.
If it has recirculating ducts I wouldn't bother with them. Way too hot!
It's also pretty easy to split the output and divert some flow to the drivers side defrost vent. I did it in my Beetle and I have almost instant (1 min.) hot defrost.
jim
Thanks for the tips, Jim. If I do install it it will probably go in a future Ghia and not mine. My heat works better than any of the 7 or 8 air cooled cars we had in the past, and ever since redesigning the floor vent controls and a few other things, it moves a lot of air. I used the defrosters last night, and a maple seed that found it way into the floor vent got blown right out of the defroster vent. However, like someone here mentioned, we will see when January rolls around 
Paul