how sure are you that you will manufacture these? i'm very keen, especially as i've now fitted my propex in the westy wheel cupboard, do you have a timescale?
Mine should be under the bench seat but a PO converted to two single seats, I don't have a wheel well, so at the mo I have two cans of tyre weld and leave the spare in the garage. If I'm doing long distances I chuck it in be back and then slide it under the van when camping. My ultimate plan is to get a roof rack big enough to fit a spare on.
with a standard size 185/80/14 you can't - or at least it will not sit inside the roof part - on a rear hinge - FACT i mauled mine up to try it.