Well I did this to my car this weekend, and love the idea!!

The only thing I changed was that instead of using a new spring on the outside of the shifter like in the pictures above, I used my dremmel to cut some of the center out of the black piece of plastic so that it has a pocket for the original spring to sit into. Accomplishes the same thing, but this way you dont have to find a new spring for it.

Oh yeah, looking back at the pictures, I noticed you used a new shift knob as well. I just reused my original one so that I dont have to deal with hot metal shifters in the summer. You just do the opposite of how you take them off, boil them in water a while, put it back on and make sure its lined up, then stick it in the fridge for a bit so it tightens up again.