Here's one of the Mustang on my Ultra. Please excuse the mess in my garage...

 

I just bought the Mustang Tripper Solo w/ the p-pad for my Fat Bob, which is a two piece version of the Daytripper. It keeps a lower profile than Sundowner and had a pretty good rep from the posters on this board and elsewhere. I wanted better long-haul comfort, but didn't want the huge Sundowner (and I got the Mustang seats at a good price, which helped).