Just having completed my Silvio build, I have discovered there is not a lot of off-the-rack storage gear that fits Silvio well, short of adding a rack. After thinking about it a little I came up with a simple, low-cost approach to add 3.6 liters of under-seat storage on Silvio. I started out with Sofrider. The Radical Designs Solo Aero fit nicely on the Sofrider - not so on the Silvio. Searching the Forum for ideas, I found several options, but none that were particularly suited to my style of bicycling. I am not a commuter. My rides generally vary from 15 to 40 miles a day, locally. I just need a little extra space. I use plastic jars for under seat storage on my Silvio. Each jar is a 4" dia. X 9" long cylindrical container. Each provides 1.8 liters of storage. I got them at Walmart. It is what bungie cords are packaged into. Similar jars are available on the internet but most are available only in bulk quantities. Walmart was only too convenient, but boy do I have a lot of bungie cords! I used only the existing holes in the Silvio seat to attach eyelets, then attached bungie cords through the eyelets. The eyelets were purchased at the local hardware store. Excess threads were trimmed with a Dremel tool. I covered the nuts with electrical tape (not shown in this photograph) to preclude chaffing the seat fabric. You don't have to be much of a "handy-man" to do this. The underside of the seat looks like this with bungie cords attached. The finished product looks like this. You can also customize the clear plastic jar by printing your favorite message or color onto a sheet of paper and attaching it to the inside of the jar. Two of these jars can be mounted, one on each side of the seat. On the right side of the bike my jar contains things that I hope I will never use on my ride (first aid, tire repair, batteries, tools, paper towels, CO2, etc.). On the left side I have room for cell phone, wallet, jacket, etc. On short rides I will cram cell phone and wallet into the right side container, too. This implementation was at first inspired by a "Technical Tour" of the Vendetta by Jim Parker in which he described the austere manner in which Maria carried her tools - a tennis ball can. A single container -- a bit bigger than a Maria's tennis ball can-- has sufficient capacity for most of my rides. The approach has the advantage of scalability. I can add a second container to the other side or not. One can be added to the seat back, or different sized containers can be used. It's easy to clean. Although, the attachment is reasonably secure, I would not recommend carrying too much weight. My tool side container (loaded) weighs 800 grams. Yikes, that sounds like a lot! As a point of reference, my filled 21oz water bottle weighs in at 700 grams. The photograph below shows the jar without the logo. The logo was printed on an 8 ½ X 11 sheet of paper on an inexpensive ink jet printer. I like the Road-Runner image - Beep, Beep. Sorry for the reflection across the image. Oh yea, don't try this on your diamond frame. Finally, thanks to all who have posted to the Cruzbike Forum. I have scoured the Forum for months gathering ideas and insights into this fantastic machine! Hopefully, someone will find my post as valuable as I have found yours.