Eastwood has it listed, summit does not. (I thought Summit bought Eastwood and sold everything on summit's site as well?)

It's expensive, but it's the right thing to use for glass and paint. I REALLY wish I had. also note you need it when grinding too. I've destroyed several windows just grinding in the area (some VERY hard to replace- like a 63 1/2 Galaxie windshield!)..
When arc and MIG welding, a couple feet horizontal clearance is about all you need. If TIG, it's not really an issue since you shouldn't have metal flying around.

When grinding, any exposed glass within 10-15 ft needs to be covered since those damn sparks fly everywhere and in every direction!