One or more of the following factors may have caused this failure to occur: the normal wear of hitting bumps, or temperature differences in the summer (i.e. sudden a/c cooling after sitting in 90 deg heat). i can't think of any other cause. the clear plastic window the driver sees through when viewing the speedometer started to crack in multiple places. over time the cracks increased in size. the consequences are primarily cosmetic, but could also pose a slight hazard while trying to read the numeric readouts and indicators. honda replaced the part for free using the warranty, but as i suspected this problem has occurred a second time. this could prove a major headache if i have to replace the instrument cluster window once/year. i'd like a stronger plastic or glass replacement if possible. *nm