Don't know about the front LT/RT lenses but the rear running lights will, after many miles, start to warp the lens slightly from the heat of the filament in the bulb.
On my K75 I installed LED bulbs with an LED-friendly relay and inverted the signal from the relay so they're always on full-on as running lights and flash off for turns. I wouldn't try this with filament bulbs as I'm sure the heat of a normal bulb would melt the lens.
(http://i82.photobucket.com/albums/j246/smithduck/k75f/K75f_running_lights.jpg)