fairly popular to swap out the rear incandescents with LEDs. Given that LED technology is now well developed, not expensive, has a long life span along with superior illumination times* compared to incandescents - it's hard to justify sticking with old style bulbs IMHO.
*LEDs light just over 1/2 second faster than incandescents. At 55mph the car following you is traveling at 80 ft/s - that .5 seconds translates to a 40 ft better margin of reaction to a braking situation. At 75mph the margin is 55 ft.