Quality / Replacement mattress
I'd like to comment on the "hard mattress". I tried laying on a memory foam mattress in a store, and I hated the thing. I felt like it swallowed me up, I couldn't even roll over. They are very popular now, so it must be personal preference. That said, it was time to replace the mattress in our BT Cruiser and I found a standard innerspring to our liking at "The Original Mattress Factory". There is a store near me, which allowed me sample their various offerings and choose the firmness I needed.
I have no connection to this company other than I like their products, so I will share this information. First of all, everything they sell is made to order. You order it, they build it and in a few days it will be shipped to your home. They can build any combination you can imagine, so you can order a soft mattress that will fold wherever you want it to, just give them the measurements.
My 2005 BT Cruiser 5270 has a queen bed, and part of it lifts up for access to water pump, drain valves, etc. They said they would "hinge" it in the middle, which they did. They were also familiar with a "short queen", which is common in RVs. To make getting around the end of the bed easier, I asked them to make it one inch shorter, which they did, no problem. Of course if you need the length, you won't want to do that.
Lastly, there are no returns, so be sure you specify exactly what you need, and if you need it to fold at a certain location, be sure to tell them you need it to fold way over (assuming 180 degrees?), not simply bend to lift it. They make a good product, in the USA, which is refreshing these days. Website is originalmattress dot com.
One final note, although they are a custom builder, they do not cost any more than other brands.
If anyone buys from this store, I'd like to hear their comments and how it worked out for them, and if they could get a "split" mattress.