icarlisle. Listen to me. Having an old car for nice days is a sweet romantic notion that will be shattered by flat batteries, corroded exhausts, shagged clutches and seized brake calipers.
If you buy a Spider, you must use it regularly, not just in the summer. If you don't use it in the winters, you must prepare it for periods of hibernation in an appropriate environment.
Not trying to put you off, but I left mine unattended for a year (long boring story). I'm still reeling from the financial kick it subjected me to when it came to sale time. Do it, but do it properly.