I've had more cars than I dare mention and yet the one I remember with most affection was my first- a Hillman Avenger. Why? Because I really enjoyed driving it and working on it and using it- sitting on the bonnet with my girlfriend, getting stuck in mud etc. Some cars however- because they are perfect and expensive become too much of both to be enjoyed- you worry about scuffing the wheels, or marking the paintwork- or yes- geting the interior wet. We worry about reducing their value and yet- when you go to a car show I for one am more drawn to the worn, clearly enjoyed cars than the concours. Oh and leather enjoys getting wet- it is dryness that destroys it.
I suppose what I am saying is just get out and enjoy your car. Roof up or roof down- just use the car. If something wears out, replace it.