Wolfgang,
I also collect 1/43 models. I've probably got 100+ in that scale but also have some 1/24 and 1/18 if the car I like is in that scale. I just measured some of my 1/43s and they run between 3 3/4" to about 4 1/2". My Speedster 1/43 is 3 3/4" long. They are about as short as any of them although my bug eye Sprite may be a tad shorter. Get your ruler out and measure yours and see if they aren't all about the same as mine. I think 1/43 is about as small as I want to go with my aging eye sight, LOL.
I started with the 1/18 scale but soon found that displaying them would soon need a whole room, cases also become an issue also. I am needing another case for some additional 1/43 that I want to display. They are in the origional boxes and I tend to forget which ones I have if i can't see them.
What genre of 1/43s do you collect? When I lived in Chicago they put on a 1/43 only show every year, still do. It was THE place to go for the serious collector. Always bought too may each year but glad I did.
Bruce