While newer seals are less likely to dry out, other things can affect the car if it sits. I got my car after it had been driven less than 2k miles a year. The first repair I had to do was fix a vacuum due to fuel in the lines crystalizing.
After being on this forum for a year and doing a lot of reading, weekend/summer only Boxster's tend to have far more problems than the ones driven regularly. So to answer your question it would be a good idea to start the car every few days, and if you want to avoid any more problems don't store it, drive it!
These cars where made to be driven!
