1. Current Configuration: I currently have a Caribou Cases 1550 on my 2006 R1200GS. http://cariboucases.com/Rear-Top-Ca...ou-35-Liter-Pelican-Rear-Top-Case-System.html (As a matter of fact...that's MY bike shown). The Pelican 1550 case is a nice addition to my BMW OEM Aluminum panniers...and come with the following specs: <table id="ip_table_two"><tbody><tr><td>Weight 10.58 lbs. - Empty 11.90 lbs. - With Foam</td> </tr> <tr class="alt"> <td>Exterior Dimensions 20.62" x 16.87" x 8.12" (L x W x H)</td> </tr> <tr> <td>Interior Dimensions 18.43" x 14.00" x 7.62" (L x W x H)</td></tr></tbody></table> Do the calculations and you'll see that those Interior Dimension produce 1966 cubic inches...or about 32.2 cu LITERS. 2. I want to have more space in my TOP CASE. I had the opportunity to pick up a NEW Pelican 1600 from a fellow inmate in the Vendors section who had excess cases from his company. Source: http://advrider.com/forums/showthread.php?t=985277&highlight=pelican+1600 Here are the specs for the the 1600: <table id="ip_table_two"><tbody><tr><td>Weight 13 lbs. - Empty 14.11 lbs. - With Foam</td> </tr> <tr class="alt"> <td>Exterior Dimensions 24.25" x 19.43" x 8.68" (L x W x H)</td> </tr> <tr> <td>Interior Dimensions 21.43" x 16.50" x 7.87" (L x W x H)</td></tr></tbody></table> Doing the same calculations with the 1600 you get 2782 cubic inches or 45.5 cu LITERS...or 41% MORE than the 1550. 3. More volume...but yikes...am I going to have to buy ANOTHER cargo plate for it? After carefully examining the 1550 Cargo Plate...I discovered that I could MOVE the 4 original Caribou mounting pucks to another pre-drilled location on the same plate....and USE BOTH CASES with the same plate. Here's a picture of the 1550 plate with the pucks MOVED to their new locations. The arrows on the BLUE tape indicate their original locations. Update: See Post #4 for a Puck Mounting TIP. Here's a pic of the plate mounted on the 06 GS...note plenty of clearance from the side cases. And this gives you and idea of how the 1550 fits...mounted to the plate. It pretty much matches up with the OEM cases for positioning toward the rear of the bike. And...there's room left ahead of the case for the Rider...wearing a normal riding jacket the case actually provides a nice back rest enroute. I also have a 1-Gallon Rotopax mounted on the opposite side from the muffler. Note how the TOP of the RotoPax 1-gallon is flush with the top of the 1550 making a nice platform for tents, sleeping bags, etc. Here's the 1600 mounted...USING THE SAME plate. Both use the Caribou quarter turn fasteners. While the 1600 extends OVER the BMW OEM panniers...there is still clearance above the top of the lids...which can be easily removed. !" spacers are used to lift the mounting plate off the plastic housing. Here's a side view of the 1600 over the aluminum panniers. After carefully deciding WHERE to mount the 1600 on the plate...I decided to LEAVE my back rest! Note that there's about the same amount of space behind the riders seat. The case extends a little further rearward...but still short of the extremity of the tail light. Another pics of the space behind the rider's seat. Case CAME with foam for medical equipment...I ripped out everything but the top foam. Since the 1600 has 4 LATCHES (2 on the sides)...I can't exactly replicate how I carried my 1-Gallon RotoPax with the 1600. However, I discovered this position might do just as well. 4. Summary. With a little planning I was able to USE 1 mounting plate to accommodate 2 different Pelican cases...that provide different amounts of carrying capacity. Overall...a good 3 hour project.