We got a huge set of cheap bags we use for trips off of Ebay. Cost about $50 and are cavernous. They hold up well for use but don't stay looking good very long. If you just want use out opf them then remove once you reach your destination they are great if you want to leave them on all the time I don't reccomend them.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!