i just did this mod to my car today, did it with the red sleeves over the existing bulbs. i must say i am very happy with the result
the hot spots do exist, but hardly noticable at night. also added some lettering to my dials and painted the edges of the guages white, came out quite nice!! only thing is with my guage faces, the backing was all the green plastic, not just the back paint, so i get a green tinge regardless... very weird :S however at night it isnt even noticable. thanks for a great tute