Byron, your situation is a little different from others who are considering selling a car they’ve owned for years because it doesn’t interest them to the same extent that once it did.
You have the prospect of a Porsche GT product to distract you from the impending loss of a car you’ve cherished and developed for most of your adult life. For you, there’s a tough trade ahead, but one that will ultimately lead to a phenomenal car and (hopefully) increased opportunities and visibility for your business. I’m certain you don’t want to sell your Zed, but your want for the Porsche exceeds the dissonance you’re anticipating when you say goodbye to your pride and joy! If the opportunity was there, wouldn’t you want to own them both?
In an idle moment, I’ve thought about selling all my impractical cars and consolidating into one - if I did, I’d probably buy a McLaren 650S spider and be bankrupted by maintenance costs! However, I love the contrasting spectrum of cars I own at present, from a thumping V8 through to a light-weight screaming inline 4, via a beautifully balanced straight 6. I don’t think I want to lose any of them, especially my Zed after so many years of history together. The result for me is that I keep buying ever more cars and trying to find ways to justify it… It’s becoming more difficult with two young kids who’ll soon want to come along for the ride, so perhaps there’s change in my future too.