Had toppers on three of my motorhomes - - - hated them. Never leave your slides out in a windstorm - - lost two in a storm and wrapped one around the motorhome while driving. Last motorhome did not have them and my fiver does not. Noisy. Stuff (like birds and squirrels) get underneath them and try to build nests if you are stopped for a few days. Try getting that out before bringing in the slide. Guy beside me in a fiver on Fundy Bay in Nova Scotia had to leave his slides in while there because of the constant winds. His layout was lousy for living in without slide deployed. Nope - - no toppers for this kid. Some models like the Carriage (as stated) have a flat roof with no lip on the end therefore do not hold debris when the slide comes in.
Bob