Mark IV- Thanks for that feedback. I 'll take your word for it. The SPF Cobra I rode in Friday with the under car set up was 15 years old, so I thought I better check this out in the event I pursue a later model SPF when I'm ready.
This leads me to another question, a little "outside the box". If I purchased a used SPF with side pipes, and then installed an under car exhaust, would it just be crazy talk to think of fabbing up a painted glass square panel, say an 1/8" to 1/16" smaller in its dimensions than the glass side-pipe cut-outs and insert in the side pipe holes, not as a permanent patch, but as a removable panel for re-installation of sidepipes at a later date? It would be easy enough to brace it. I imagine this would work better aesthetically with darker colors. I am also sure there will be as many different opinions on this as there are owners, but I recognize the popularity of sidepipes should I ever decide to sell the one roadster, and buy another in the future. Plus it opens up lots of buying opportunities for used versus being constrained to ordering new just to get under car exhaust. Probably over analyzing this.
Slow Monday morning.