MINGZHE 100 PCS 1/64 Scale Model Car Display Case Transparent Toy Car Display Boxes Square Clear Plastics PVC Transparent Box Display Case Exhibition Box Accessories(Clear)

https://www.amazon.com/dp/B0CP9W5TK7?ref=ppx_pop_mob_ap_share There are others. You can probably find better deals but this was the last one I purchased. There's one brand that has slightly sturdier plastic than this particular brand but it costs a tiny bit more.