MDR-97-Z71
400 Obsessor
Could be that the bases of the LEDs are slightly too tight or too loose in the sockets compared to regular bulbs. I've noticed that the tolerances don't seem to be very tight on LEDs.
This makes sense to me.. I never thought to check if the light held better while parked than driving, I can't imagine there's many fixes for this situation. It mostly bugs me cause I hate things not matching, so I'd rather have everything be blue or all regular bulbs.