Don, when my 84' was new, I had the same sort of angst. It is well within the normal range( I am declaring both you and I normal). When overnight at a hotel I used to pull off the negative cable on the battery! My wife thought I was nuts. No, normal! Truthfully it is never left outside at home, while other brand new cars(just got a red 08' Malibu LTZ-sweet little car!) are left out in the rain wherever they get parked. 89' Porsche Carreras are special, and there aren't all that many of them around. Don't listen to those other guys. An old Carrera is special, just like your girl or wife.
Glenn