Off the top of my head, Revell made a 1/32 XKE, K&B made a 1/24 Cobra GT... lots of other companies made the XKE, it's one of the most produced slot cars in history, but there were very few in 1/24. It was mostly made in 1/32 and smaller scales.
K&B also made a 1/32 Cobra GT, as did Auto Hobbies, while Lindberg made a 1/24 model, as did Monogram (a slightly different version, vac-form body).
No lack of either of these cars in almost any scale!
Don
Here's a beautifully detailed (not by me...) K&B Cobra Daytona:
Lindberg and Otaki Cobra GTs:
A Marx convertible XKE in a slightly oversized 1/32 scale
A Strombecker XKE, also oversized 1/32:
Those are just a sampling, from my photo library...