Me and Jody are pals but I disagree.
When I look at your car, I see race car. The mixture of race car and street car is what brings the money for a "Pro Touring" car. The ultimate goal is to make your car mimic a modern sports car. We all know it's impossible to achieve that but close is good enough.
Here's why I feel I'm right. How many guys on Lateral-G are really racing their cars compared to a weekend warrior? 1 out of 20 or greater. Even though I like to race my car, it still spends more time on the street. That means dynamat, carpet, windows that roll up, a heater, radio.
I'd certainly exhaust all the regular avenues before I changed the car. You may want to figure out the cost to make those changes and offer it as a contingency of the sale after a large deposit. The only negative is they may not be able to see the outcome. It's like a house that shows like crap, most people don't have much vision.