Hallo,
there is a Kit from Andy's Modellbau in Germany for Slotcars in 1:24 in GfK, look here:
http://andys-modellbau.eshop.t-onlin...20GFK%20Kit%22
This Kit based on an Burago Diecast Model and is not so scale you like.
From the 924 GTS and GTR are also Kits from DITECH Production in Germany, but i dont know if you can buy it.