My daughter in laws birthday is coming up and she is into red glassware so I was wondering if anyone knows how to wrap a cake to look like glass.

Ooooh wow! How gorgeous would that look!
I'm sorry I can't help with how to do it but would also love to hear suggestions

You could make some poured sugar. You could break it up and make some stained glass. You can also use piping gel to get a shiny affect. Just tint it with some red coloring. Gelatin is also another choice. The easiest would be tinting the piping gel. You can pipe it directly onto the cake.

Here are some examples of cakes decorated with piping gel.

http://www.cakecentral.com/cake-photo-6054.html

http://www.cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1215895

http://www.cakecentral.com/modules.php?name=gallery&file=displayimage&pid=5789

http://www.cakecentral.com/modules.php?name=gallery&file=displayimage&pid=973603


http://www.cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1107693

I hope this gives you some ideas....