Spyder Man wrote: "It's certainly enough heat in a Spyder, interior is much smaller than a Speedster."
So if my wife calls my Speedster a "Clown Car", does that make your Spyder a "Mini-Clown-Car" or a "Micro-Clown Car"?
Gas heaters really throw a lot of heat, though. Mine extended my driving season by 3-4 months a year, and I run it pretty much on "low-ish".
I'm also running mine as a "flow through" (taking in fresh air from outside) and haven't yet seen the need for a defroster/defogger. But then, I haven't been out in any downpours with the top up, either.
Bruce: If you're looking for for a nice, compact system for your Suby-Spyder, look at the offerings from Vintage Air
Look at their "Builder's Series" I think the "Mini" would fit, but they have a "Compact" version, too. That's the most popular line of heaters used by the Hot Rod set - I think Carey Hines uses them, too. They offer both kits and individual parts, even the dash bezels separately. Good place to start.
https://www.vintageair.com/bui...amp;subcat2=Heritage