Sell the car and get a schit-box. You'll be much happier. Porsche ownership isn't for everyone, IMO, and for lots of people it's more ass-pain and expense than fun. That expense can be measured in time worrying for people like you, or time and energy obsessing about mods and upgrades plus just mental energy thinking about the car when you could be thinking about something better. You have to always count the time it took you to earn the $$ for the car and mods or track time into the equation.
The happiest owners of Porsches, (or Ducatis/Ferraris/M5s/whatever), are people who can easily afford them and are not total car nuts w/ the OCD that most of us have here. Objects should give you enjoyment over stress at a fairly high ratio, or not be possessed.
An '88 targa is not even on the radar of car thieves
AFAIK, unless there is a new demand for them overseas somewhere and they are getting thrown in shipping containers. Within the U.S., young people look at them like a 356 or something, a slow funny-looking car that old dudes drive. I've thought about getting a newer Honda Civic Si as a driver because of fuel prices, but that's a car that actually
does get stolen a lot, so it would be a PITA. Trust me, no one in the 'hood wants a 1988 targa. They would have to wear parachute pants w/ a giant flat-top haircut and pump MC Hammer when they drove it. And that crowd is not really big on irony last time I checked.
As for door-dings on a pristine car, that I understand a little better. If you have a perfect car, (new or old), you can't park it in supermarket or mall lots and expect it not to get dinged. The car is less usable as a driver and more hassle if you want to avoid dings. Paying valets extra to keep it in front, etc.. Every Porsche I've ever owned has been a used car w/ dings, the last 3 are all 10 or 20-footers, IOW beautiful from across the street but plenty of stone-chips up close. My current 996 is parked absolutely anywhere, including Home Depot between beat-up PU trucks, it's used as a pack-mule for hauling stuff and taken to the track or out to dinner. I enjoy it thoroughly, never work on it and if I got hit in it I would profit hugely if not killed or maimed. Life is short, dude. Fly to Mexico and bang some whores or something, you're wound like an 8-day clock.
