I loved the Floppy for my last 2 children. It just made me feel better to know that they were in a seat that was a bit more cushy. It was really great when they were just starting to sit up and I could easily put my purse or a stuffed animal next to them to help coax them into position. It is also great at times when they fall asleep. The Wendy Bellisimo is very nice as well. As a matter of fact, I think it is made by Floppy. The KozyPalsKart cover is super nice as well. With the last one, you are able to pick out your own fabric. They are usually at the Baby Faire each year so they will be there this coming weekend with many samples, clearance items and regular priced items for sale. All 3 of these will double as a restaurant high chair cover.
The back of the cart is another subject. I have not found anything to help, shy of covering the entire cart in a sheet, that will keep that area "safe". I just wing it when it is needed.
Many have said that we shouldn't put our children in a bubble. This is a very true statement and is why so many of our medications are not as effective as they used to be. When we moved to Texas, my 2nd was about 18 months old and I did not unpack the Floppy Seat right away. It took me about 2 months to piece things together that I was constantly taking him to the doctor with sinus and ear infections. I started using the Floppy again and he didn't get sick any longer. To me, it's worth it on many levels to have this seat cover and now that it has gone through 2 children with only fabric fading and the tag coming off, it was money well spent!