Here is a Dutch Fiero forum. http://www.fiero.nl/cgi-bin/fiero/Ultimate.cgi?action=intro Ebay shows 44 available when searched for Fiero in passenger vehicles
I know for a fact that some of the Cadillac remotes work. I have been using one for over a year now. It does have four buttons with one of them being the interior illumination button. I would start the troubleshooting with a known to be working remote, it just takes a minute to program, see www.reatta.net for programming instructions.
Try this old THREAD The way I got it was I went to the search page, keyed A\C conversion into the Words to search for box, and here's the sutile part, change the Date Range box to All posts, Not all problems come up in a week.
Smart cars are really hot in Europe, in Amsterdam I see lots of them. Here's a site for a roll your own. http://www.thesmart.co.uk/ I see they even have a roadster available.