TCM 01 CL-S

To make a long story short, my rear window has a nice 18 inch scratch in it, not too deep, but deep enough for your fingernail to get caught in. Took it to Rick Case Honda down the street which has a very large and popular body shop for an estimate and they said that it would have to replaced. I expected they would say that since they have to guarentee their work for life.

Is there anyway to have this kind of damaged glass professional repaired? I've seen many places online that do automotive glass repair (most with lifetime guarentee), Pros/cons to doing so, etc?