Besides weather related exposures and consequences more/less that others have mentioned already, the hardtop has considerable value and is easy to remove --- break open just one of the door windows and the hardtop's just 4 simple lever's away from being lifted right off, zero other damage or risk of any. Two guys can do the deed in 2 minutes max ----break window, move levers, lift it off, and put it in a small van and drive off.
The other factor to leaving it exposed is all the interior chrome. Condensation (humid interior if any leaks, or just humid atmosphere) will corrode the chrome surfaces (interior mirror, chrome bezels on instruments, chrome levers (for hard-top/soft-top release), if hardtop's on then chrome levers at attachment behind the doors, and the chrome covers on the body behind the doors. This will occur even in sunny CA Santa Clara Valley in summer even due to warm / hot days, and cooling at nite with fog (or just humid air) rolling over the coast range or down from SF bay, so it will occur the more-so in Netherlands.... even much, much more if near larger bodies of water (especially brine or salt marshes/canals with saltwater).
If you take meticulous care of the interior chrome... keep well waxed everywhere in in each nook/cranny of chrome, AND air out the car's interior frequently... like every other day, imo, rain or shine, then perhaps you can keep the interior chrome from corroding or tarnishing, but without that kind of constant attention you'll see interior chome tarnish, then start raising little nibs, and before you know it you'll need to have every piece rechromed. Believe it or not, the exterior chrome will fare far better than the interior chrome if car's buttoned up and non-leaking.... but not being constantly aired out.