You have chosen some personal customizations that for most people, take away from these cars. If you are to sell them, I suggest that you remove all the contrasting colors on the wheels, engine bay, interior, and trim. No red, blue, or gold paint, vinyl, or fabric anywhere. Paint your wheels silver on both cars. Use factory amber indicator lenses and factory headlights. Remove all excess BMW roundels, and any BMW motorsport roundels. The e9 already has 8 roundels on the exterior, and a roundel on the valve cover. We know it is a BMW.
Some of these modifications you have done are too personal. It is akin to having family photos up when you sell your home. Market your car to what the buyer wants, not what you want. Don’t fool yourself into thinking that your style modifications are so novel that they increase the value of your car. The most outrageously modified e9’s still don’t deviate in this department. You can do whatever you want just accept that polarizing personal touches reduce your target audience.