Check these out.
Over the past few years (Yuma Flea Market) I've replaced all of the halogens in our '06 Dynasty except for the bedroom bulbs which don't see a lot of service. (I have lots of "used" spares, now).
First, the leads are a little long so you have to cut off about 3/32" or so.
Second, whatever you do, BE SURE AND GET BULBS RATED FOR WELL OVER 12 VDC. These are rated for an operating range from 8 volts to 30 volts. Some charging systems can produce instantaneous values that can be fatal to LED's.
Third, these absolutely do work well with the mid 2000's Intellitec multiplex system devices. Knock on wood, but our failure rate has been phenomenally low! In fact, out of about 30 that I've put in with an average age now of probably 3 years, we've had zero failure. (We "live" in our coach approximately 50% of the time, so these lights have been extensively used.). We did lose a couple of the early attempts that were not rated for the higher voltages. But these "Green" Longlife devices have been great, for us.