Just to let anyone considering doing this know that I had to go back in today after losing the driver's side LED completely at some point over the last year and having the front one only working on an intermittent basis, when the shifter was rocked towards the N position.
In doing so, I completely expected one of the tiny wires soldered to the LEDs to have come adrift, since that was the one point where any possibility of movement existed, and was completely and utterly surprised to find that it was actually the factory solder joint to the resistor in both instances that had failed.
So in redoing the whole setup I'm taking the opportunity to secure all the LEDs with a dab of clear silicone in addition to the band of heat-shrink I've previously used (I had already said I thought that wasn't a bad idea). In addition, I'm thinking of combining the positive wires of each LED into a bundle and soldering them to a single resistor instead of each having it's own, so that I have fewer points of potential failure and a slightly beefier wire bundle to solder on. Do the IEEEs have any comment on potential pitfalls in doing this? I've tried it already on the bench and it appears to work, but I can't think of any long-term consequences. A reminder that the resistors are 1000 Ohm each.