Checking “Mirror” doesn’t help. I’ve seen it done, it appears to be only in 32 bit, though the thread is from 2008.
I was watching this thread since I had the same question. What’s the answer?
In multi-texture mode, you can go into the Image, go to View > Properties, and select Reflection Map instead of UV-coordinates, though this may not work if you have a material present. If you have one, go to the image on the material, and use Reflection coordinates. GLSL mode is the same.
EDIT: It’s View > Properties in the UV-Window for the first method.
Aha, thanks SolarLune. This should really boost my race car’s coolness.