We have had our 05 H2 for about a year now and never noticed what appears to be a cracked luggage rail. I say "appears" since the crack is nearly perfectly vertical and very smooth. It is over the rear passenger door. If it were over both the passenger and driver's side, we'd just assume it was a spacing in the rail for whatever reason. Anyway, here are some pictures. Can anyone verify if this is a crack or is it supposed to be there? Also, I have looked at some parts diagrams online and cannot tell what the part is...
The luggage rack is behind it...
Not sure what the name of it is to order a new part. Thanks

 

It does not belong there, it's a crack. The bad news is that I don't know of anywhere that it is available new. You may have to find it in a junk yard. Another option is to remove it, glass in the back of it to repair it and make it stronger. Then reinstall.

Good Luck!

 

I have the same exact crack in the same exact place on my 06 H2. It doesn't concern me at all, the roof bars are frozen in place because they must have been tightened down by Hulk Hogan. The only reason it would bug me would be if it caused the roof racks to get caught on them, if not i consider it the cost of getting older. It is odd that its cracked in the same spot though, mine also appeared to be almost vertical. I'm not with my truck at the moment after spring break I'll be able to tell you more.

 

I have the same crack but I thought the guys who put on my gobi rack did it. Who knows. Doesn't bother me either, hard to notice unless you're looking for it.

 

I think this is the oem part if you're interested in replacing it.

Hummer GM 03 09 H2 Roof Rack Rail Luggage Carrier Side Rail Right 15241412 | eBay

 

Well done Blitz! I just noticed you are in Chesapeake, small world. I live in Great Bridge.

 

Thanks for the information and part number. I too consider this a part of an aging vehicle, though I do intend on fixing it. For $250, I can live with it for a month or so though. Just dropped $450 on an oil leak last month.