I understand and admire your sentiments, having owned 2, 4 seaters for that exact reason you mention. However, I have carried luggage externally on my first 2 seater 4/4. To be honest I have never felt happy with either of these arrangements, as under both circumstances the luggage is in plain sight and therefore may attract the wrong attention, making parking up any where whilst loaded a potentially fraught experience, I could do without.
It's bad enough with an open topped car that there really hasn't that much secure cubby hole space for small things let alone big suitcases in plain sight.
I would have to see the overall design of the car. as to whether the boot adds or detracts from the shape of the car and how practical the boot really is.
I can understand this statement. My wife is always worried about that too, I'm a bit more relaxed.
Has anyone here ever lost anything from their car or even an entire suitcase from the luggage rack while parked?