Jean-Paul- Do you live in California, by chance? 40 deg? That's spring weather man! In this part of the world, winter is cold and long and very windy. My heat is not "non-existant", just inadequate to heat the cabin to 60 deg or so on a reasonably short drive on a day colder than 20 to 30 deg, which means December to March. I have been working dilignatly on sealing the air leaks, and I have original german heat exchangers. My heat runs in PVC, not the frame rails. I think a thermostat would help a lot, as would re-circulating cabin air (instead of using 10 deg air from the engine bay). I am committed to making the car as usable as possible, but I think we are talking about two different kinds of winter here.
Bruce- I have plexiglass side-curtains with seals which I fabricated to fit the hard-top. Part of the problem with side-curtains and the soft-top is the top itself- the sealing surface along the top edge of the side-curtains is a bit "floppy", and the portion behind the doors "scoops" air into the cabin. The hard-top is a major improvement, but is difficult to safely store. I have built a padded crate, which is rugged enough to truck freight the top, but heavy as all get-out. I'm glad to be topless for the next 6 months.
Brian and Ron- Thanks for your honesty.
George- You win.
The point I was trying to make is that we all just kind of live with these cars with the tops up. Visability is poor, the cabin is noisy, it's cold in the winter. Its fun in the same way that camping in the snow is fun- its different, and kind of manly. But once the top goes down, my car becomes nearly perfect. It sounds better, it runs better, and it is fun w/o any excuses.
To get back to the original point- that makes a speedster and a spyder not all that much different. They are more alike than a speedster and a Z3, or Boxter, or MR2 Spyder, or any other "modern" car.