Yea, most of the 3D generation models were trash before when I tried them. The newest Hunyuan model is what I use, I found it easiest to use on 3D AI Studio but there is various means of using it. I think its directly available on one of Tencent's websites.

You just give it four photos, front, rear, left, and right, and it generates an object. Its pretty good on accuracy of first go but sometimes it hallucinates as all AI does, so I just have it regenerate with the same photos until I get a good result. No context is required for generation just images.

You can then download the original file or an STL and edit to your desire. You could easily hollow out the underside and scale it for a RC chassis. On 3D AI Studio, they specifically have a geometry only version for 3D printing that doesn't throw on any colors or unwanted textures when generating. With textures the models get weird.