Flambeau will sell you one of these for $18.

 

I decided to make my own from some material Walmart sells called Pro Tuff Outdoor Fabric. It's a waterproofed heavy canvas that is $4.97 per yard. For less than $10 in materials I made two of these:

  

 

 

They hold six large boxes and keep the rain from getting into the boxes underneath the lid lips.

 

Other than the two hours of diagnosis/adjustment I needed to get the sewing machine working, the hardest part was working out the correct dimensions to cut the cloth pieces. If someone wants to make one just let me know and I will post the dimensions.

Very nice work sir.

I made an open top version from some outdoor canvas I bought at a different store. It was more expensive and not waterproof, but I bought it first. I should have just started at Walmart.

 

Aren't you the crafty person,looks nice.

That's great! How long have you been using the red one? Does the durability seem to last? 

Just made it, so no data on durability.