Since I purchased my jeep, I have had a vibration sound that seems to come from the driver's door/floor area. The first time I had it looked at, the dealer found that the window glass had come out of its channel. Second time I had it in for the repair the window had fallen out of its channel again. I was told that they put the glass back in the channel and "re-enforced" it. I am still getting this vibration sound and the dealer refuses to make a repair cause they can't determine where it is coming from. This vibration seems to happen at light acceleration/engine load mostly at highway speed when the engine is at or just above 1500rpm. Anyone else experience something similar?