Spare tyre

Is there a a carrier for a spare under the van? If not I'd leave it in the garage, much handier to get to anyway. If you really want it located underneath best talk to the dealer and see if they can do it for you, If you go the DIY route or get a third party to fit the spare It would probably invalidate the warranty should there be an issue down the line.

Having a carrier and wheel under the van I had the misfortune to change a puncture once, now I have breakdown recovery and will let them do it as it was very difficult to get out once the van was dropped at one side. Keep it in the garage!

I know where I'm carrying mine after been on crutches for 2.1/2 months

Took ours out last weekend to check mechanism,grease everything and fitted the original un used tyre to the back to replace a worn one. At least we know now how it all works.

I have only had 2 punctures and 2 blowouts in 37 years of motorhoming. Both punctures were my fault when I ran over tent pegs at 2 different campsites. A French garage charged me £32 to fix one of the punctures. One of the blowouts happened when I was flying a rounder a corner in Yugoslavia and ran into a landslide. I removed the spare wheel and carrier from under the van and carry it in the garage. A 16 inch wheel is heavy to manhandle from under the van.

I don't think I would waite until some dark wet night to find out if doesn't work. you should go out and stick a nail in it just for peace of mind