It is a current phenomenon due to the unusualness of the car. It'll die down.
One way to stop them from touching it is to add a "shock" alarm to the present one so that any motion of the car will set it off. Lifewise, a proximity alarm would also be useful; it would set off when approached to whatever limits you can set.
So far as cleaning it up, my favorite window cleaner is white vinegar and water, mixed about a cup of vinegar to a gallon of water. Put some into an old squirt bottle and keep a clean towel handy. Also, Windex has introduced a version of their glass cleaner which has the same mix and works almost as well. Just don't use the stuff on "Chrome" on this car (which is polished aluminum) and the vinegar may mark the stuff. However, Windex is Windex and has a bit of a waxy content which sometimes makes the windows reflective and may be uncomfortable for your eyes.
As for getting the fingerprints off the car finish, a good brand of auto polish kept in the trunk will do wonders for getting that stuff off. Anyway you look at it though, you will have to do the work if you can't convince the persons otherwise to stay farther away.
The alarm mods, IMO, are the best way and keep the other stuff handy for use as required.
'Course, you can always park somewhere else, out of the mainstream. But, do you want to do that?
It's the price we pay for an outstanding and unusual auto. :^))
