Leave it or Hot Rod it?

It's a nice car, but it will never be a high dollar car that was ruined by tasteful mods. A lot of cars selling lately are modified to have later model systems. It makes them more comfortable to drive. If you can keep the wife happy by making the car what she wants, great. If you change the car, and she doesn't use it, at least it will be a comfortable, good driving car that may potentially be worth more in the end.