There are a lot more interesting models in this scale than mentioned throughout this thread. I am much more familiar with vintage ones, so I have to mention great series of plastic Le Mans/Can Am models by French maker Champion, dating from around 1970. They also did superb series of 1/43 models in many liveries, sometimes still cheaply available at eBay. Italian Penny and Dutch Best Box had series of Formula 1 cars in 1960s. Penny and their compatriots Speedy had very nice sportscar models, too. Other classic modelmakers also did some racing cars from time to time, of course.
Of more recent issues there are a lot of great rally cars. CM is probably the most readily available at true 1/64 scale. More of toys, Majorette did quite a few rally cars, and worth finding but quite rare are ones from Spanish Guisval, from late 1990s. Probably the favorite series, although not in racing liveries, is a great 1/64 Mille Miglia series by Japanese Yow Modellini, but they could be quite expensive these days.
As a good overview of the scale, I can recommend the great website by my friend Sinisa Pismestrovic, https://sinicars.at/ - not dedicated to racing models, though, but there are some and others can give you ideas of what is actually available of at least possible to find with a good amount of dedication. Myself, I am more dedicated to 1/43 but still have a few thousand smaller scale models, including most of the ones I mentioned above.
