There is a whole thread of many pages about this...
The reason you get an after glow is because for some unknown reason, there is a constant very low voltage which is always circulating the BCM. The reason why this low voltage is effecting some circuits is because your replacing regular bulbs with LEDs, which need much less power to operate. so when you Replace regular bulbs with LED's, you have much less load on the circuit, resulting in the slight glow of those LED's.
To resolve this, you will need to either keep existing regular bulbs and add LEDs, or add a load resistor in place of those bulbs. It also depends on your LED's, obviously Coby picked a good set of LEDs, they actually compensate for the load, so either get the same LEDs as coby, or add something which will use more power than the LEDs, or a load resistor.
LEDs are not lame, you just simply do not know enough about what your working with to get it working right.
Old Car: Chevy Cobalt 2006 LS Sedan base (Automatic)
New Car: Chevy Impala 2011 LT Fully Loaded (Automatic)